feat: VoIP PoC

[aleksandernsilva]

Proposed changes

This PR is a proof of concept for adding VoIP capabilities to our mobile app.

The implementation covers:

• Establishing SIP communication between the app and FreeSWITCH using SIP.js
• WebRTC media handling via react-native-webrtc
• Integration with the native caller UI via react-native-callkeep
  • Receiving a making extension calls
  • Ability to hold and mute calls
  • Sending DTMF messages
  • Call transfers via DTMF messages
  • Ringtone, ringback, DTMF tones
• Push notifications
• Mantaining calls in background

Work In Progress PRD-18

Related ADR's

• Agnostic voip ecosystem for team collaboration ADR 0088
• SIP Communication ADR 0120
• Caller UI ADR 0121
• Push notifications [TBD]

Issue(s)

How to test or reproduce

Screenshots

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• Improvement (non-breaking change which improves a current function)
• New feature (non-breaking change which adds functionality)
• Documentation update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works (if applicable)
• I have added necessary documentation (if applicable)
• Any dependent changes have been merged and published in downstream modules

Further comments