based on the discussions of this PR we might should add new functions to the CollectionCatalog interface in order to call them with the global lock held.

Now the CollectionCatalog::lookupCollectionByUUIDForMetadataWrite and CollectionCatalog::lookupCollectionByNamespaceForMetadataWrite works differently based on the readOnly flag of the context and the status of the global lock.

With global lock held we don't need an active WUOW to get writable catalogs.