Support firestore

[dinoboff]

Need a new security rule parser, a new runtime to evaluate rule condition and new data layer.

[wcandillon]

It looks like there is grammar/parser yet available but hopefully they will provide tooling soon.

[dinoboff]

For reference:

• Testing rules with google api explorer.
• CEL specs.

[balazsorban44]

Out of interest, is there progress on this? :crossed_fingers:

[laurentpayot]

@balazsorban44 https://firebase.google.com/docs/firestore/security/test-rules-emulator