Multi db url (#998)

MultiDB commits - fix a million tests, override reactfire's dependency on firebase to 10.x.x

Multi-db banner notice (#969)

* Multi-db banner notice

* Revert some changes, adjust copy

Limited the number of documents in the collection viewer to 9500. (#935)

* Limited the number of documents in the collection viewer to 9500. This
is to resolve an issue where the Firestore emulator is hitting a 10k
webchannel queue limit.

* Lint

* Lint

* Update Collection.tsx

Removed a trailing comma on import list.

Limited the number of documents in the collection viewer to 9500. (#935)

* Limited the number of documents in the collection viewer to 9500. This
is to resolve an issue where the Firestore emulator is hitting a 10k
webchannel queue limit.

* Lint

* Lint

* Update Collection.tsx

Removed a trailing comma on import list.