Add better UI for loading state when loading recordings

[allansson]

The UI looks pretty bad when loading large recordings. Right now it's just a text in the top-left corner saying "Loading...". We should add a centered spinner or something.

Screen.Recording.2025-03-11.at.20.10.54.mov

[vansh-nagar]

I’d like to work on this issue. Please assign it to me.

[allansson]

Thank you for you interest in the project! It's always great to see people wanting to help out.

This was actually addressed in #829 and was released in 1.8.0. The issue was not linked to the PR so it wasn't closed when that PR was merged.

Closing it now.