Mark channel owner with owner keyword

[KhaledKamalA]

🔗 Issue Links

Add related Linear and/or GitHub issues, if applicable.

🎯 Goal

Visually indicate the channel owner in the UI by marking them with an “Owner” keyword.

📝 Summary

• Added an “Owner” label next to the channel owner’s name
• Updated channel member views to highlight the owner
• Ensured consistency with existing UI styles and spacing
• No impact on other member labels or functionality

🛠 Implementation

• Introduced a computed property to identify the owner in ChatChannel or ChatChannelMember
• Updated relevant SwiftUI views to display the Owner keyword
• Applied existing text styles for consistency with other labels
• Verified that marking does not affect performance or accessibility

🎨 Showcase

The screenshots below show the UI before and after adding the “Owner” label.

Before	After

🧪 Manual Testing Notes

1. Open a channel with multiple members
2. Verify the channel owner is displayed with the “Owner” keyword
3. Check consistency across Channel Info, Member List, and other relevant screens
4. Confirm no regressions for non-owner members

☑️ Contributor Checklist

• I have signed the Stream CLA (required)
• This change should be manually QAed
• Changelog is updated with client-facing changes
• Changelog is updated with new localization keys
• New code is covered by unit tests
• Documentation has been updated in the docs-content repo