### Godot version

v4.2.dev3.official [013e8e3af]

### System information

Windows 11, Core i5-12400F, RX 6600

### Issue description

TileSet->Setup->Separation maybe should have "px" like rest?
![Screenshot 2023-08-21 162202](https://github.com/godotengine/godot/assets/962340/3c6b9a97-7520-4610-8153-7882cc9c303f)
I know this is pixels from testing it.

TileSet->Select is this Animation Separation "px" too? idk
![Screenshot 2023-08-21 162131](https://github.com/godotengine/godot/assets/962340/fcb580e3-9ff7-41d8-92d3-e585841d3803)
I tried setting up animation separation and got a not enough room error, so maybe not "px". idk


Thanks.


### Steps to reproduce

- open TileSet->Setup->Separation, note some have "px" and one doesn't
- open TileSet->Select, is this separation "px" too?


### Minimal reproduction project

n/a
if (!tile_set_atlas_source) {
		return;
	}
	Ref<Texture2D> texture = tile_set_atlas_source->get_texture();
	if (texture.is_valid()) {
		Vector2i margins = tile_set_atlas_source->get_margins();
		Vector2i separation = tile_set_atlas_source->get_separation();
		Vector2i texture_region_size = tile_set_atlas_source->get_texture_region_size();
		Vector2i grid_size = tile_set_atlas_source->get_atlas_grid_size();
		EditorUndoRedoManager *undo_redo = EditorUndoRedoManager::get_singleton();
		undo_redo->create_action(TTR("Remove tiles in fully transparent texture regions"));
		List<PropertyInfo> list;
		tile_set_atlas_source->get_property_list(&list);
		HashMap<Vector2i, List<const PropertyInfo *>> per_tile = _group_properties_per_tiles(list, tile_set_atlas_source);
		for (int i = 0; i < tile_set_atlas_source->get_tiles_count(); i++) {
			Vector2i coords = tile_set_atlas_source->get_tile_id(i);
			Vector2i size_in_atlas = tile_set_atlas_source->get_tile_size_in_atlas(coords);
			
			if ((coords.x + size_in_atlas.x) > grid_size.x || (coords.y + size_in_atlas.y) > grid_size.y) {
				continue;
			}
			
			Rect2i region = Rect2i(margins + (coords * (texture_region_size + separation)), texture_region_size * size_in_atlas);
			bool is_opaque = false;