Permanent overlay in preview view and culling view not refreshed correctly

As I explained in issue #20252, tooltips and extended overlays were not refreshing properly.

PR #20253 correctly fixed the tooltips for the lighttable, but not the tooltips and extended overlays for the preview view. In addition, I discovered that the same thing happens with the tooltips and extended overlays in the two culling views.

This is annoying because, especially in the preview view, the color labels are displayed via permanent overlays, but the color labels are located on the far right and are very small, barely visible. I had never seen it until @wferguson pointed it out to me. Yet, I have been using darktable for a very long time ;-). This is definitely a UI flaw that should also be fixed.

There is another possible solution, which is to separate the display of the permanent overlay from the display of the extended overlay. In other words, today we can have the following display:

• Nothing

• Permanent Overlay alone

• Extended overlay AND permanent overlay

It would be nice to have:

• Nothing

• Permanent overlay alone

• Extended overlay alone

• Extended overlay and permanent overlay

This is possible today because it is now possible to add the variables $(LABELS.ICONS) and $(RATING.ICONS) in the definition of extended overlays. We can therefore do without the display of permanent overlays.

Would it be possible to improve the interface in this way?