Tile animation marker gets in the way of Terrain labels #3785

Problem

When editing Terrains in a tileset that has animations defined, the animation marker in the corner of the tiles can get in the way, even though it's drawn below the labels - it obscures the tile art and makes it harder to know what the label should be, and in some cases, it can be hard to tell whether there's a label there at all.

Proposed solution

It would be nice if, when the Terrain Sets editor is open, the animation markers were drawn with a lower opacity, so that the tile art beneath is visible, and so that they don't overwhelm low-contrast terrain labels. Hiding them entirely would not be good, as they're often useful to know which tiles should get terrain labels and which should not.