Update the worker images once an image is added or removed.

[francois2metz]

This fix a bug when a fallback image was not used when it was added via addImage.

For instance, the following style with a missing image nonexistant and an added image shop would show nothing.

   "icon-image": [
      "coalesce",
      ['image', 'nonexistant'],
      ['image', 'shop']
    ]

I also updated the list of images on the worker when an image is removed to keep it synchronized.

[ryanhamley]

Hi @francois2metz can you open an issue that corresponds to the problem this PR is trying to fix, including a minimal example of the bug? I think this change makes some sense but I want to ensure that this doesn't cause unnecessary tile loads.

[francois2metz]

@ryanhamley Good point, I did it: #9900

[karimnaaji]

This looks great @francois2metz , I confirm the behavior. Thanks for adding a description of the issue. I continued this PR in #9911 with render test coverage, which is confirmed to fail on main branch. We can close this PR and continue the discussion there.