Feat: App Positioning Feature Backend Implementation (#19514)

## Description

Implements backend functionality for App Positioning (Auto Layout)
Feature

Fixes #19348 


## Type of change

- New feature (non-breaking change which adds functionality)


## How Has This Been Tested?

- JUnit 
- Manual


## Checklist:
### Dev activity
- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my own code
- [x] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [x] PR is being merged under a feature flag


### QA activity:
- [ ] Test plan has been approved by relevant developers
- [ ] Test plan has been peer reviewed by QA
- [ ] Cypress test cases have been added and approved by either SDET or
manual QA
- [ ] Organized project review call with relevant stakeholders after
Round 1/2 of QA
- [ ] Added Test Plan Approved label after reveiwing all Cypress test

app/server/appsmith-server/src/main/java/com/appsmith/server/domains/Application.java

@@ -114,6 +114,11 @@ public class Application extends BaseDomain {
 
     NavigationSetting publishedNavigationSetting;
 
+    @JsonIgnore
+    AppPositioning publishedAppPositioning;
+
+    @JsonIgnore
+    AppPositioning unpublishedAppPositioning;
 
     /**
      * Earlier this was returning value of the updatedAt property in the base domain.
@@ -179,6 +184,8 @@ public class Application extends BaseDomain {
         this.icon = application.getIcon();
         this.unpublishedAppLayout = application.getUnpublishedAppLayout() == null ? null : new AppLayout(application.getUnpublishedAppLayout().type);
         this.publishedAppLayout = application.getPublishedAppLayout() == null ? null : new AppLayout(application.getPublishedAppLayout().type);
+        this.unpublishedAppPositioning = application.getUnpublishedAppPositioning() == null ? null : new AppPositioning(application.getUnpublishedAppPositioning().type);
+        this.publishedAppPositioning = application.getPublishedAppPositioning() == null ? null : new AppPositioning(application.getPublishedAppPositioning().type);
         this.unpublishedCustomJSLibs = application.getUnpublishedCustomJSLibs();
     }
 
@@ -281,4 +288,36 @@ public class Application extends BaseDomain {
         private Boolean showShareApp;
     }
 
+    public AppPositioning getAppPositioning() {
+        return Boolean.TRUE.equals(viewMode) ? publishedAppPositioning : unpublishedAppPositioning;
+    }
+
+    public void setAppPositioning(AppPositioning appPositioning) {
+        if (Boolean.TRUE.equals(viewMode)) {
+            publishedAppPositioning = appPositioning;
+        } else {
+            unpublishedAppPositioning = appPositioning;
+        }
+    }
+
+    /**
+     * AppPositioning captures widget positioning Mode of the application
+     */
+    @Data
+    @NoArgsConstructor
+    public static class AppPositioning {
+        Type type;
+
+        public AppPositioning(Type type) {
+            this.type = type;
+        }
+
+        public enum Type {
+            FIXED,
+            AUTO
+        }
+
+    }
+
+
 }

app/server/appsmith-server/src/main/java/com/appsmith/server/services/ce/ApplicationPageServiceCEImpl.java

@@ -1011,6 +1011,7 @@ public class ApplicationPageServiceCEImpl implements ApplicationPageServiceCE {
                     application.setPublishedPages(pages);
 
                     application.setPublishedAppLayout(application.getUnpublishedAppLayout());
+                    application.setPublishedAppPositioning(application.getUnpublishedAppPositioning());
                     if (isPublishedManually) {
                         application.setLastDeployedAt(Instant.now());
                     }

app/server/appsmith-server/src/test/java/com/appsmith/server/services/ce/ApplicationServiceCETest.java

@@ -2210,6 +2210,7 @@ public class ApplicationServiceCETest {
         String appName = "ApplicationServiceTest Publish Application";
         testApplication.setName(appName);
         testApplication.setAppLayout(new Application.AppLayout(Application.AppLayout.Type.DESKTOP));
+        testApplication.setAppPositioning(new Application.AppPositioning(Application.AppPositioning.Type.FIXED));
         Mono<Application> applicationMono = applicationPageService.createApplication(testApplication, workspaceId)
                 .flatMap(application -> applicationPageService.publish(application.getId(), true))
                 .then(applicationService.findByName(appName, MANAGE_APPLICATIONS))
@@ -2241,6 +2242,7 @@ public class ApplicationServiceCETest {
                     assertThat(newPage.getUnpublishedPage().getLayouts().get(0).getDsl()).isEqualTo(newPage.getPublishedPage().getLayouts().get(0).getDsl());
 
                     assertThat(application.getPublishedAppLayout()).isEqualTo(application.getUnpublishedAppLayout());
+                    assertThat(application.getPublishedAppPositioning()).isEqualTo(application.getUnpublishedAppPositioning());
                 })
                 .verifyComplete();
     }
@@ -2264,6 +2266,7 @@ public class ApplicationServiceCETest {
         String appName = "Publish Application With Archived Page";
         testApplication.setName(appName);
         testApplication.setAppLayout(new Application.AppLayout(Application.AppLayout.Type.DESKTOP));
+        testApplication.setAppPositioning(new Application.AppPositioning(Application.AppPositioning.Type.FIXED));
         Mono<Tuple3<NewAction, ActionCollection, NewPage>> resultMono = applicationPageService.createApplication(testApplication, workspaceId)
                 .flatMap(application -> {
                     PageDTO page = new PageDTO();
@@ -2364,6 +2367,7 @@ public class ApplicationServiceCETest {
     public void publishApplication_withGitConnectedApp_success() {
         GitApplicationMetadata gitData = gitConnectedApp.getGitApplicationMetadata();
         gitConnectedApp.setAppLayout(new Application.AppLayout(Application.AppLayout.Type.DESKTOP));
+        gitConnectedApp.setAppPositioning(new Application.AppPositioning(Application.AppPositioning.Type.FIXED));
 
         Mono<Application> applicationMono = applicationService.update(gitConnectedApp.getId(), gitConnectedApp)
                 .flatMap(updatedApp -> applicationPageService.publish(updatedApp.getId(), gitData.getBranchName(), true))
@@ -2394,6 +2398,7 @@ public class ApplicationServiceCETest {
                     assertThat(newPage.getDefaultResources()).isNotNull();
 
                     assertThat(application.getPublishedAppLayout()).isEqualTo(application.getUnpublishedAppLayout());
+                    assertThat(application.getPublishedAppPositioning()).isEqualTo(application.getUnpublishedAppPositioning());
                 })
                 .verifyComplete();
     }