## Description
Added cypress test for add pane interactions.
Fixes#31868
## Automation
/ok-to-test tags="@tag.All"
### 🔍 Cypress test results
<!-- This is an auto-generated comment: Cypress test results -->
> [!CAUTION]
> Workflow run:
<https://github.com/appsmithorg/appsmith/actions/runs/8504922496>
> Commit: `0c74a26f4c959c84bf308876e4c0740e0c45ca90`
> Cypress dashboard: <a
href="https://internal.appsmith.com/app/cypress-dashboard/rundetails-65890b3c81d7400d08fa9ee5?branch=master&workflowId=8504922496&attempt=1&selectiontype=test&testsstatus=failed&specsstatus=fail"
target="_blank"> Click here!</a>
> The following are new failures, please fix them before merging the PR:
<ol>
>
<li>cypress/e2e/Regression/ClientSide/AppNavigation/AppNavigationWithMultiplePages_spec.ts
</ol>
> To know the list of identified flaky tests - <a
href="https://internal.appsmith.com/app/cypress-dashboard/identified-flaky-tests-65890b3c81d7400d08fa9ee3?branch=master"
target="_blank">Refer here</a>
<!-- end of auto-generated comment: Cypress test results -->
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
- **New Features**
- Introduced test cases for adding panes in the IDE, covering various
tab interactions.
- Added the ability to switch between full screen and split screen modes
in the IDE.
- **Tests**
- Added a new Cypress custom command for easier test maintenance.
- **Refactor**
- Enhanced testability by adding `data-testid` attributes across various
IDE components for improved element selection in tests.
- Improved code clarity through reorganization and reformatting of
component properties.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Co-authored-by: Hetu Nandu <hetunandu@gmail.com>