Cloner functionality and import improvements

This update resolves issues with cloner functionality and enhances the import process for multiple objects.

Changes

• Cloner error fixes.
• Cloner undo/redo now works.
• Lights undo/redo now works.
• Fix text creation issue.
• Now it is possible to import several objects/images at the same time.
• Now there is an auto-resize of textures.
• Fixed issue with copy/paste from inputs or from outside into Spline.
• Fixed issue with the context menu when UI is hidden.