Optimize metadata queries (#7013)

In this PR:

1. Refactor guards to avoid duplicated queries: WorkspaceAuthGuard and
UserAuthGuard only check for existence of workspace and user in the
request without querying the database

packages/twenty-server/src/engine/dataloaders/dataloader.interface.ts

@@ -1,7 +1,11 @@
 import DataLoader from 'dataloader';
 
+import { RelationMetadataLoaderPayload } from 'src/engine/dataloaders/dataloader.service';
 import { RelationMetadataEntity } from 'src/engine/metadata-modules/relation-metadata/relation-metadata.entity';
 
 export interface IDataloaders {
-  relationMetadataLoader: DataLoader<string, RelationMetadataEntity>;
+  relationMetadataLoader: DataLoader<
+    RelationMetadataLoaderPayload,
+    RelationMetadataEntity
+  >;
 }