Refactor graphics editor and screen editor tab handling

- Updated tab item handling in GraphicsEditor and ScreenEditor to ensure proper opening and closing of tab items.
- Improved layout management by replacing deprecated macros with ImGui table functions for better readability and maintainability.
- Adjusted palette display function signature in color handling to return a boolean for success status instead of absl::Status.
- Enhanced tile rendering functions for consistency and clarity in the graphics editing workflow.

src/app/editor/overworld/overworld_editor.cc

@@ -687,7 +687,7 @@ absl::Status OverworldEditor::DrawTile16Selector() {
   {
     blockset_canvas_.DrawContextMenu();
     blockset_canvas_.DrawBitmap(tile16_blockset_.atlas, /*border_offset=*/2,
-                                map_blockset_loaded_);
+                                map_blockset_loaded_, /*scale=*/2);
 
     if (blockset_canvas_.DrawTileSelector(32.0f)) {
       // Open the tile16 editor to the tile