fix: Using create action permission for schema generation (#37243)

Currently, schema generation uses execute permission on the datasource
to execute open ended queries for schema generation. Limiting it to
developers who have create action permission on the said datasource (and
hence have been given rights to run any query on the said datasource)
instead of execute datasource permission which is given to everyone.

## Description
> [!TIP]  
> _Add a TL;DR when the description is longer than 500 words or
extremely technical (helps the content, marketing, and DevRel team)._
>
> _Please also include relevant motivation and context. List any
dependencies that are required for this change. Add links to Notion,
Figma or any other documents that might be relevant to the PR._


Fixes #`Issue Number`  
_or_  
Fixes `Issue URL`
> [!WARNING]  
> _If no issue exists, please create an issue first, and check with the
maintainers if the issue is valid._

## Automation

/ok-to-test tags="@tag.All"

### 🔍 Cypress test results
<!-- This is an auto-generated comment: Cypress test results  -->
> [!TIP]
> 🟢 🟢 🟢 All cypress tests have passed! 🎉 🎉 🎉
> Workflow run:
<https://github.com/appsmithorg/appsmith/actions/runs/11702166169>
> Commit: 8946b48
> <a
href="https://internal.appsmith.com/app/cypress-dashboard/rundetails-65890b3c81d7400d08fa9ee5?branch=master&workflowId=11702166169&attempt=2"
target="_blank">Cypress dashboard</a>.
> Tags: `@tag.All`
> Spec:
> <hr>Wed, 06 Nov 2024 12:46:12 UTC
<!-- end of auto-generated comment: Cypress test results  -->


## Communication
Should the DevRel and Marketing teams inform users about this change?
- [ ] Yes
- [ ] No


<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **New Features**
- Updated permission model for accessing datasource schema previews,
enhancing security.
  
- **Bug Fixes**
- Improved error handling for specific exceptions, providing clearer
feedback during errors.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

app/server/appsmith-server/src/main/java/com/appsmith/server/solutions/ce/DatasourceStructureSolutionCEImpl.java

@@ -183,7 +183,7 @@ public Mono<DatasourceStructure> getStructure(DatasourceStorage datasourceStorag
     public Mono<ActionExecutionResult> getSchemaPreviewData(
             String datasourceId, String environmentId, Template queryTemplate) {
         return datasourceService
-                .findById(datasourceId, datasourcePermission.getExecutePermission())
+                .findById(datasourceId, datasourcePermission.getActionCreatePermission())
                 .zipWhen(datasource -> datasourceService.getTrueEnvironmentId(
                         datasource.getWorkspaceId(),
                         environmentId,