Refactor schema migration runner service discovery (#13988)

## Context
This refactoring improves scalability in the workspace migration runner
in terms of actions. Instead of relying on a switch case and multiple
changes and services + duplicate things between metadata and workspace
schema, we now have a unique module for all kind of actions and a
registry pattern to register them and run them dynamically.

Example on how to add a new "create_role" action with the future design:
```typescript
// packages/twenty-server/src/engine/workspace-manager/workspace-migration-v2/workspace-migration-runner-v2/action-handlers/role/services/create-role-action-handler.service.ts
export class CreateRoleActionHandlerService extends WorkspaceMigrationRunnerActionHandler(
  'create_role',
) {
  constructor(
    private readonly workspaceSchemaManagerService: WorkspaceSchemaManagerService,
    private readonly roleRepository: Repository<Role>,
  ) {}

  async executeForMetadata(
    context: WorkspaceMigrationActionRunnerArgs<CreateRoleAction>,
  ): Promise<void> {
      this.roleRepository.save({...}); // technically could use the queryRunner from context param directly instead of injecting the repository
  }

  async executeForWorkspaceSchema(
    context: WorkspaceMigrationActionRunnerArgs<CreateRoleAction>,
  ): Promise<void> {
      // this.workspaceSchemaManagerService.tableManager... -> Nothing to do in the workspace schema in the role case
  }
}
```
```typescript
// packages/twenty-server/src/engine/workspace-manager/workspace-migration-v2/workspace-migration-runner-v2/action-handlers/workspace-schema-migration-runner-action-handlers.module.ts
@Module({
  imports: [WorkspaceSchemaManagerModule, +TypeOrmModule.forFeature([Role]),
  providers: [
     ...
     +RoleCreateActionService
  ],
})
export class WorkspaceSchemaMigrationRunnerActionHandlersModule {}
```
```typescript
export type WorkspaceMigrationAction=
  | WorkspaceMigrationObjectAction
  ...
  +| WorkspaceMigrationRoleAction;

export type CreateRoleAction = {
   type = 'create_role',
   role: RoleEntity
};

export type WorkspaceMigrationRoleAction = CreateRoleAction;
```

packages/twenty-server/src/engine/metadata-modules/field-metadata/services/field-metadata.service-v2.ts

@@ -26,7 +26,7 @@ import { deleteFieldFromFlatObjectMetadataMapsOrThrow } from 'src/engine/metadat
 import { getSubFlatObjectMetadataMapsOrThrow } from 'src/engine/metadata-modules/flat-object-metadata-maps/utils/get-sub-flat-object-metadata-maps-or-throw.util';
 import { replaceFlatFieldMetadataInFlatObjectMetadataMapsOrThrow } from 'src/engine/metadata-modules/flat-object-metadata-maps/utils/replace-flat-field-metadata-in-flat-object-metadata-maps-or-throw.util';
 import { WorkspaceMetadataCacheService } from 'src/engine/metadata-modules/workspace-metadata-cache/services/workspace-metadata-cache.service';
-import { WorkspaceMigrationValidateBuildAndRunService } from 'src/engine/workspace-manager/workspace-migration-v2/workspace-migration-validate-build-and-run-service';
+import { WorkspaceMigrationValidateBuildAndRunService } from 'src/engine/workspace-manager/workspace-migration-v2/services/workspace-migration-validate-build-and-run-service';
 
 @Injectable()
 export class FieldMetadataServiceV2 {

packages/twenty-server/src/engine/metadata-modules/object-metadata/object-metadata-v2.service.ts

@@ -23,7 +23,7 @@ import {
   ObjectMetadataExceptionCode,
 } from 'src/engine/metadata-modules/object-metadata/object-metadata.exception';
 import { WorkspaceMetadataCacheService } from 'src/engine/metadata-modules/workspace-metadata-cache/services/workspace-metadata-cache.service';
-import { WorkspaceMigrationValidateBuildAndRunService } from 'src/engine/workspace-manager/workspace-migration-v2/workspace-migration-validate-build-and-run-service';
+import { WorkspaceMigrationValidateBuildAndRunService } from 'src/engine/workspace-manager/workspace-migration-v2/services/workspace-migration-validate-build-and-run-service';
 
 @Injectable()
 export class ObjectMetadataServiceV2 {