Refactor workspace migration runner exception handling (#17310)

# Introduction
In this PR we catch all the runner errors coming from a single workspace
migration action execution.

**1. `WorkspaceMigrationActionExecutionException`** (low-level,
action-specific)
- Thrown from action handlers, utils, and helper functions
- Contains specific error codes: `FIELD_METADATA_NOT_FOUND`,
`OBJECT_METADATA_NOT_FOUND`, `ENUM_OPERATION_FAILED`, `NOT_SUPPORTED`,
etc.
- Simple structure: `message`, `code`, `userFriendlyMessage`
- No action context - just describes what went wrong

**2. `WorkspaceMigrationRunnerException`** (high-level, runner-scoped)
- Only two codes: `INTERNAL_SERVER_ERROR` and `EXECUTION_FAILED`
- `EXECUTION_FAILED` **requires** `action` + `errors` (contains the
action context)
- `INTERNAL_SERVER_ERROR` **requires** `message` (no action context)

## Refactor
- Removed the `relatedFlatEntityMapsKeys` from the `WorkspaceMigration`
type as they're directly inferred from passed actions
- Swallowing actions rollbacks errors in order to iterate over all of
them

## Testing
Created a very straigthforward install application from workspace
migration endpoint in order to start testing the introduced
`WorkspaceMigrationActionExecutionException`
Introduced a feature flag that stop the access to the endpoint if not
enabled
Whole taken direction are totally subjective and highly prone to
mutations ( endpoint location, naming and input schema see
`ts-expect-error` comment )
cc @martmull 

## Response error
```ts
{
  "eventId": "evt_a1b2c3d4-5678-90ab-cdef-1234567890ab",
  "extensions": {
    "action": {
      "metadataName": "fieldMetadata",
      "type": "delete",
      "universalIdentifier": "20202020-6110-4547-9fd0-2525257a2c3f"
    },
    "code": "APPLICATION_INSTALLATION_FAILED",
    "errors": {
      "metadata": {
        "code": "ENTITY_NOT_FOUND",
        "message": "Could not find flat entity with universal identifier 20202020-6110-4547-9fd0-2525257a2c3f"
      },
      "workspaceSchema": {
        "code": "ENTITY_NOT_FOUND",
        "message": "Could not find flat entity in maps"
      }
    },
    "exceptionEventId": "exc_f9e8d7c6-5432-10ba-fedc-ba0987654321",
    "userFriendlyMessage": "Migration execution failed."
  },
  "message": "Migration action 'delete' for 'fieldMetadata' failed",
  "name": "GraphQLError"
}
```

packages/twenty-server/src/engine/workspace-manager/workspace-migration/services/workspace-migration-build-orchestrator.service.ts

@@ -1058,13 +1058,6 @@ export class WorkspaceMigrationBuildOrchestratorService {
       };
     }
 
-    const relatedFlatEntityMapsKeys = [
-      ...new Set([
-        ...Object.keys(fromToAllFlatEntityMaps),
-        ...Object.keys(dependencyAllFlatEntityMaps ?? {}),
-      ]),
-    ] as (keyof AllFlatEntityMaps)[];
-
     const { aggregatedOrchestratorActionsReport } =
       aggregateOrchestratorActionsReport({
         orchestratorActionsReport,
@@ -1075,7 +1068,6 @@ export class WorkspaceMigrationBuildOrchestratorService {
     return {
       status: 'success',
       workspaceMigration: {
-        relatedFlatEntityMapsKeys,
         actions: [
           // Object and fields and indexes
           ...aggregatedOrchestratorActionsReport.index.delete,

packages/twenty-server/src/engine/workspace-manager/workspace-migration/services/workspace-migration-validate-build-and-run-service.ts

@@ -196,15 +196,9 @@ export class WorkspaceMigrationValidateBuildAndRunService {
       return;
     }
 
-    await this.workspaceMigrationRunnerService
-      .run(validateAndBuildResult.workspaceMigration)
-      .catch((error) => {
-        this.logger.error(error);
-        throw new WorkspaceMigrationV2Exception(
-          WorkspaceMigrationV2ExceptionCode.RUNNER_INTERNAL_SERVER_ERROR,
-          error.message,
-        );
-      });
+    await this.workspaceMigrationRunnerService.run(
+      validateAndBuildResult.workspaceMigration,
+    );
   }
 
   public async validateBuildAndRunWorkspaceMigration({