Hotfix: solve issues with older projects, custom scripts, and room editor

🐛 Bug Fixes

• Fix indefinite behavior after placing copies and switching to the properties tab in the room editor
• Fix loading error while migrating a project without tile layers to v1.4.0
• Fix regression with custom script typings: they were not loaded on project load
• Fix type picker being empty right after opening the room editor
• Icons in the room editor, on the left side, should be centered if no labels are shown next to them.