### 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
}
		for (const Vector2i &E : to_paint) {
			Vector2i coords = E;
			TilesEditorUtils::draw_selection_rect(tile_atlas_control, tile_set_atlas_source->get_tile_texture_region(coords), color);
		}
	} else if (drag_type == DRAG_TYPE_CREATE_TILES_USING_RECT) {
		
		Vector2i margins = tile_set_atlas_source->get_margins();
		Vector2i separation = tile_set_atlas_source->get_separation();
		Vector2i tile_size = tile_set_atlas_source->get_texture_region_size();
		Vector2i start_base_tiles_coords = tile_atlas_view->get_atlas_tile_coords_at_pos(drag_start_mouse_pos, true);
		Vector2i new_base_tiles_coords = tile_atlas_view->get_atlas_tile_coords_at_pos(tile_atlas_control->get_local_mouse_position(), true);
		Rect2i area = Rect2i(start_base_tiles_coords, new_base_tiles_coords - start_base_tiles_coords).abs();
		area.set_end((area.get_end() + Vector2i(1, 1)).min(tile_set_atlas_source->get_atlas_grid_size()));
		for (int x = area.get_position().x; x < area.get_end().x; x++) {
			for (int y = area.get_position().y; y < area.get_end().y; y++) {
				Vector2i coords = Vector2i(x, y);
				if (tile_set_atlas_source->get_tile_at_coords(coords) == TileSetSource::INVALID_ATLAS_COORDS) {
					Vector2i origin = margins + (coords * (tile_size + separation));
					TilesEditorUtils::draw_selection_rect(tile_atlas_control, Rect2i(origin, tile_size));
				}
			}
		}
	}
	
	if (drag_type == DRAG_TYPE_REMOVE_TILES_USING_RECT || drag_type == DRAG_TYPE_CREATE_TILES_USING_RECT) {
		
		Vector2i start_base_tiles_coords = tile_atlas_view->get_atlas_tile_coords_at_pos(drag_start_mouse_pos, true);
		Vector2i new_base_tiles_coords = tile_atlas_view->get_atlas_tile_coords_at_pos(tile_atlas_control->get_local_mouse_position(), true);
		Rect2i area = Rect2i(start_base_tiles_coords, new_base_tiles_coords - start_base_tiles_coords).abs();