[Enhancement]Provide call rejection reason

[ipavlidakis]

🎯 Goal

Provide a rejection reason based on this specification.

🛠 Implementation

Rejection reason should be added only on methods handling explicit user requests (we shouldn't include any rejection reason in methods that respond to call events).

Due to changes the following breaking changes have been introduced as they remove unnecessary code from IncomingCallViewModel

• the hideIncomingCallScreen property
• the stopTimer method.

☑️ Contributor Checklist

• I have signed the Stream CLA (required)
• This change follows zero ⚠️ policy (required)
• This change should receive manual QA
• Changelog is updated with client-facing changes
• New code is covered by unit tests
• Comparison screenshots added for visual changes
• Affected documentation updated (Docusaurus, tutorial, CMS)

[sonarcloud]

Quality Gate passed

Issues
32 New issues
0 Accepted issues

Measures
0 Security Hotspots
69.6% Coverage on New Code
0.1% Duplication on New Code

See analysis details on SonarCloud