Fix member list not updated after moderator is demoted

[nuno-vieira]

🔗 Issue Links

Resolves https://github.com/GetStream/ios-issues-tracking/issues/785

🎯 Goal

Fix the member list not updated after the moderator is demoted.

📝 Summary

At the moment, the backend does not fire any event to notify that a moderator has been demoted or promoted. So, if we have a moderator in the local DB that was demoted, it won't be removed from the local DB, so it will never be deleted.

🛠 Implementation

Even if the backend does not fire any event, we should also make sure that when opening the member list for the first time, that we clear the cache, to make sure that removed members do not get included in the response.

🧪 Manual Testing Notes

Note: Make sure you have the latest update of stream-cli on your machine.

1. Add moderators to a channel through the CLI, example:
   stream-cli chat promote-moderators --type messaging --id 2884427A-E r2-d2 leia_organa
2. Open the Demo App
3. Swipe the channel and tap on "..."
4. Then tap on "Show Channel Moderators"
5. You should see the added moderators
6. Go back to the Channel List
7. Demote one of the moderators:
   stream-cli chat demote-moderators --type messaging --id 2884427A-E leia_organa
8. Open the channel moderators again
9. You should only see "r2-d2"

☑️ Contributor Checklist

• I have signed the Stream CLA (required)
• This change follows zero ⚠️ policy (required)
• This change should be manually QAed
• 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)

[testableapple]

LGTM 🙌

[sonarcloud]

Quality Gate passed

Issues
53 New issues
0 Accepted issues

Measures
0 Security Hotspots
88.8% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud