Ability to query Database with arbitrary ID

[dhetharia]

Is your feature request related to a problem? Please describe.
Yes. Multiple database have been GA for a little bit now. From what I've seen, I cannot specify the Database I want to query with FireQL.

Describe the solution you'd like
One of two things, in order of desirability.

1. Query like so: select * from [DATABASE ID].users limit 1.
2. Add the database ID when instantiating the client. This is unnecessarily limiting and requires changes in various clients. Myself, I'd like to use the Grafana plugins, which would then need updating. Option 1 would be my preference.

Describe alternatives you've considered
I searched through the code for about 20 minutes to see if there was an option provided for this and couldn't find it. Another alternative is migrating my database, but that's a non-starter.

Additional context
https://cloud.google.com/blog/products/databases/firestore-multiple-databases-is-now-generally-available