Is your feature request related to a problem? Please describe.

Running more than one instance of Firestore in isolated, disposable contexts is not possible, as the underlying connection makes it impossible for these clients to be cleared from memory.

An example would be to use Node.js VM.

Describe the solution you'd like

I'd like to see an API to close all open streams, so the client can be garbage collected.

Describe alternatives you've considered

Hacking my way into @grpc/grpc-js, which exposes this API.

Additional context

Here's an example of what it can cause :)