Metadata modules for PageLayoutTab PageLayoutWidget (#16662)

# Introduction
Creating dedicated folders and module for both `page-layout-tab` and
`page-layout-widget`

The addition diff with deletion is due to the module being added

packages/twenty-server/src/engine/metadata-modules/flat-page-layout/flat-page-layout.module.ts

@@ -2,7 +2,7 @@ import { Module } from '@nestjs/common';
 import { TypeOrmModule } from '@nestjs/typeorm';
 
 import { WorkspaceFlatPageLayoutMapCacheService } from 'src/engine/metadata-modules/flat-page-layout/services/workspace-flat-page-layout-map-cache.service';
-import { PageLayoutTabEntity } from 'src/engine/metadata-modules/page-layout/entities/page-layout-tab.entity';
+import { PageLayoutTabEntity } from 'src/engine/metadata-modules/page-layout-tab/entities/page-layout-tab.entity';
 import { PageLayoutEntity } from 'src/engine/metadata-modules/page-layout/entities/page-layout.entity';
 
 @Module({

packages/twenty-server/src/engine/metadata-modules/flat-page-layout/services/workspace-flat-page-layout-map-cache.service.ts

@@ -8,7 +8,7 @@ import { WorkspaceCacheProvider } from 'src/engine/workspace-cache/interfaces/wo
 import { createEmptyFlatEntityMaps } from 'src/engine/metadata-modules/flat-entity/constant/create-empty-flat-entity-maps.constant';
 import { type FlatPageLayoutMaps } from 'src/engine/metadata-modules/flat-page-layout/types/flat-page-layout-maps.type';
 import { transformPageLayoutEntityToFlatPageLayout } from 'src/engine/metadata-modules/flat-page-layout/utils/transform-page-layout-entity-to-flat-page-layout.util';
-import { PageLayoutTabEntity } from 'src/engine/metadata-modules/page-layout/entities/page-layout-tab.entity';
+import { PageLayoutTabEntity } from 'src/engine/metadata-modules/page-layout-tab/entities/page-layout-tab.entity';
 import { PageLayoutEntity } from 'src/engine/metadata-modules/page-layout/entities/page-layout.entity';
 import { WorkspaceCache } from 'src/engine/workspace-cache/decorators/workspace-cache.decorator';
 import { regroupEntitiesByRelatedEntityId } from 'src/engine/workspace-cache/utils/regroup-entities-by-related-entity-id';

packages/twenty-server/src/engine/metadata-modules/flat-page-layout/types/flat-page-layout.type.ts

@@ -6,7 +6,7 @@ export const pageLayoutEntityRelationProperties = [
   'objectMetadata',
   'tabs',
   'application',
-] as const;
+] as const satisfies (keyof PageLayoutEntity)[];
 
 export type PageLayoutEntityRelationProperties =
   (typeof pageLayoutEntityRelationProperties)[number];