☂️ React Native Firebase refactor

[russellwheatley]

What is happening

• Moving away from namespaced API and matching as closely as possible the Firebase JS SDK modular (v9) API. Naturally, the native SDK specific API will remain which doesn't exist on the Firebase JS SDK.
• Migrate React Native Firebase modular API fully to Typescript.
• Migrate React Native Firebase to leverage Turbo Modules away from the legacy bridge.

Work Required

This might be subject to change depending on what challenges we come across, but roughly speaking, the below noted is what we expect to do to achieve the above:

1. Deprecate namespaced API:

• core
• firestore
• auth
• storage
• perf
• app check
• crashlytics
• remote config
• analytics
• real time database
• messaging
• in-app-messaging
• functions
• installations
• app-distribution

2. Migrate modular API to Typescript including removing dependency on underlying namespaced API.
3. Migrate to Turbo Modules
   1. Create Typescript specification for communicating with native platform via Turbo Modules.
   2. Update Typescript bridge code.
   3. Update the native code to implement Turbo Module interfaces.
   4. Update build configuration changes (i.e. build gradle and podspec), update Metro configuration and code generation configuration.
4. Update RNFB documentation.