Fix: Images no longer flash white

[Luke-Schreiber]

Does this PR close any open issues?

Closes #212

Give a longer description of what this PR addresses and why it's needed

• Images no longer flash white after each load

Additions: Removed old code comments + minor refactoring

Provide pictures/videos of the behavior before and after these changes (optional)

[Dev-Lan]

• add visual indication (loading icon/animation) when the different layers are still loading and are not yet in sync
• Visual indicator is small lives in header, triggered by any layer change, less flickery (maybe debounce, out of sync for 50 milliseconds)

[Luke-Schreiber]

Working on moving the visual indicator to the header

[Luke-Schreiber]

Working on moving the visual indicator to the header

done!

[Luke-Schreiber]

Now I'm making the 'loading...' less flickery

[Luke-Schreiber]

Removed flickering, just need to resolve conflicts

[Luke-Schreiber]

Resolved merge conflicts, just reviewing the code to try and remove unneeded complexity

[Luke-Schreiber]

Resolved merge conflicts, just reviewing the code to try and remove unneeded complexity

Done