[Plugin] Add Firebase CLI support

[passwordless-OTP]

Add enhanced completions for Firebase CLI with caps annotation.

Features

• Parse firebase.json for projects/sites
• Complete hosting sites and channels
• Complete functions with trigger types
• Firestore collections (cached)
• Storage buckets

Aliases to Add

• firebase-deploy-hosting
• firebase-deploy-functions
• firebase-emulate-all
• firebase-firestore-export

References

• https://firebase.google.com/docs/cli

/label enhancement,new-plugin
/milestone v0.3