feat: add GetConversationEpochFromCC use case and integrate into debug conversation screen

[MohamadJaara]

What's new in this PR?

Issues

The debug inspect conversation screen showed the epoch from the local conversation object, which is not reliable enough for debugging.

Solutions

• Kept the existing local epoch visible and marked it as deprecated.
• Added a new debug use case to fetch the conversation epoch from CC.
• Added a small refresh action because the CC epoch is fetched on demand and not exposed as a flow.
• Displayed the CC epoch as a separate line in the inspect conversation screen.

Testing

Test Coverage

• I have added automated test to this contribution

How to Test

• Verified the new Kalium use case with unit tests.
• Verified the debug conversation ViewModel with unit tests.
• Ran static analysis successfully.

Notes

The CC epoch is only available for MLS conversations.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud