Page layout refactoring (#14535)

In this PR:
- Refactored the page layout renderer
- Converted all the states to component states
- Removed the page layout edition in settings

TODOs in next PRs:
- Fix bug with the drag selector not taking the scroll into account to
display the dragged area
- Readd the tab edition in edit mode

packages/twenty-front/src/modules/app/components/AppRouter.tsx

@@ -1,9 +1,7 @@
 import { useCreateAppRouter } from '@/app/hooks/useCreateAppRouter';
 import { currentUserState } from '@/auth/states/currentUserState';
-import { useIsFeatureEnabled } from '@/workspace/hooks/useIsFeatureEnabled';
 import { RouterProvider } from 'react-router-dom';
 import { useRecoilValue } from 'recoil';
-import { FeatureFlagKey } from '~/generated/graphql';
 
 export const AppRouter = () => {
   // We want to disable serverless function settings but keep the code for now
@@ -15,17 +13,9 @@ export const AppRouter = () => {
     (currentUser?.canImpersonate || currentUser?.canAccessFullAdminPanel) ??
     false;
 
-  const isPageLayoutFeatureFlagEnabled = useIsFeatureEnabled(
-    FeatureFlagKey.IS_PAGE_LAYOUT_ENABLED,
-  );
-
   return (
     <RouterProvider
-      router={useCreateAppRouter(
-        isFunctionSettingsEnabled,
-        isAdminPageEnabled,
-        isPageLayoutFeatureFlagEnabled,
-      )}
+      router={useCreateAppRouter(isFunctionSettingsEnabled, isAdminPageEnabled)}
     />
   );
 };