Restore the skipped compat Firestore and Storage specs #3822

The browser test suite skips every spec for three compat Firestore classes and one compat Storage spec, so CI does not check those APIs:

• src/compat/firestore/collection/collection.spec.ts, src/compat/firestore/collection-group/collection-group.spec.ts and src/compat/firestore/document/document.spec.ts call pending("These are pretty broken, investigate.") in their top-level beforeEach, which skips every spec in those files (AngularFirestoreCollection, AngularFirestoreCollectionGroup, AngularFirestoreDocument). This came in with More v19 enhancements #3586.
• Inside the first two files, four more specs carry their own pending for flakes with Firebase SDK v11, and will need the same look once the beforeEach skip is gone.
• src/compat/storage/storage.spec.ts skips "should upload, get metadata, and delete" with pending("Not sure why this is busted.").

The compat support statement in docs/compat.md (#3810) commits to bug fixes for these APIs, so their specs should run. The work is to find out why each one was disabled, fix the spec or the code, and remove the pending calls.