fix: curl import empty headers issue fixed (#23982)

## Description
This PR fixes:
- When we import api request using curl and if api request does not have
any header values, the imported request looks like below, empty key
value headers are missing.
<img width="764" alt="Screenshot 2023-06-02 at 1 30 34 PM"
src="https://github.com/appsmithorg/appsmith/assets/30018882/21b70393-ea05-4281-ba3e-b1819c907dd5">

#### PR fixes following issue(s)
Fixes #19214 
> if no issue exists, please create an issue and ask the maintainers
about this first
>
>
#### Media
> A video or a GIF is preferred. when using Loom, don’t embed because it
looks like it’s a GIF. instead, just link to the video
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>
#### Type of change
- Bug fix (non-breaking change which fixes an issue)
>
>
>
## Testing
>
#### How Has This Been Tested?
> Please describe the tests that you ran to verify your changes. Also
list any relevant details for your test configuration.
> Delete anything that is not relevant
- [x] Manual
- [ ] Jest
- [x] Cypress
>
>
#### Test Plan
> Add Testsmith test cases links that relate to this PR
>
>
#### Issues raised during DP testing
> Link issues raised during DP testing for better visiblity and tracking
(copy link from comments dropped on this PR)
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>
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## 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
- [ ] New and existing unit tests pass locally with my changes
- [ ] PR is being merged under a feature flag


#### QA activity:
- [ ] [Speedbreak
features](https://github.com/appsmithorg/TestSmith/wiki/Test-plan-implementation#speedbreaker-features-to-consider-for-every-change)
have been covered
- [ ] Test plan covers all impacted features and [areas of
interest](https://github.com/appsmithorg/TestSmith/wiki/Guidelines-for-test-plans/_edit#areas-of-interest)
- [ ] Test plan has been peer reviewed by project stakeholders and other
QA members
- [ ] Manually tested functionality on DP
- [ ] We had an implementation alignment call with stakeholders post QA
Round 2
- [ ] Cypress test cases have been added and approved by SDET/manual QA
- [ ] Added `Test Plan Approved` label after Cypress tests were reviewed
- [ ] Added `Test Plan Approved` label after JUnit tests were reviewed

---------

Co-authored-by: “sneha122” <“sneha@appsmith.com”>

app/client/cypress/e2e/Regression/ServerSide/ApiTests/CurlImportFlow_spec.js

@@ -63,4 +63,14 @@ describe("Test curl import flow", function () {
       });
     });
   });
+
+  it("3. Bug:19214 Test curl import flow for request without any headers", function () {
+    cy.fixture("datasources").then((datasourceFormData) => {
+      _.dataSources.FillCurlNImport(
+        "curl -X GET " + datasourceFormData["echoApiUrl"],
+      );
+      _.apiPage.AssertEmptyHeaderKeyValuePairsPresent(0);
+      _.apiPage.AssertEmptyHeaderKeyValuePairsPresent(1);
+    });
+  });
 });

app/client/cypress/support/Pages/ApiPage.ts

@@ -409,4 +409,9 @@ export class ApiPage {
     if (apiName) this.agHelper.RenameWithInPane(apiName);
     cy.get(this._resourceUrl).should("be.visible");
   }
+
+  AssertEmptyHeaderKeyValuePairsPresent(index: number) {
+    this.agHelper.AssertElementVisible(this._headerKey(index));
+    this.agHelper.AssertElementVisible(this._headerValue(index));
+  }
 }

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

@@ -427,9 +427,7 @@ public class CurlImporterServiceCEImpl extends BaseApiImporter implements CurlIm
             }
         }
 
-        if (!headers.isEmpty()) {
-            actionConfiguration.setHeaders(headers);
-        }
+        actionConfiguration.setHeaders(headers);
 
         if (!dataParts.isEmpty()) {
             if (MediaType.APPLICATION_FORM_URLENCODED_VALUE.equals(contentType)) {