fix(unlock-app): Improve event collections UX

[0xTxbi]

Description

This PR introduces changes that fixes some ux issues with event collections

ScreenGrabs

• Fixed loading state

  

• Banner uses cover image if none was initially provided upon creation

  

• Confirmation modal to remove manager

  

Issues

Fixes # Refs #

Checklist:

• [x] 1 PR, 1 purpose: my Pull Request applies to a single purpose
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have updated the docs to reflect my changes if applicable
• [ ] I have added tests (and stories for frontend components) that prove my fix is effective or that my feature works
• [x] I have performed a self-review of my own code
• [ ] If my code involves visual changes, I am adding applicable screenshots to this thread

[0xTxbi]

Please add screenshots/videos for these.

sure, done!