Add Curve Tools and Curve Selection/Copy/Paste

[maiko3tattun]

Please merge #1811 first 🙏

New Features:

• Add CurveSelectTool, CurvePenTool, CurveEraserTool
  • Selecting a curve will deselect the note.
  • The selection range affects the snap state of the pianoroll.
  • The Curve Eraser Tool now allows you to reset curves with a left click, improving usability on laptops.
• Add Copy/Cut/Paste Curve function
  • The last item copied from either the notes or the curve will be pasted.

Code Refactoring:

• Compact code for setting curves within a specified range

Not Yet:

• I couldn't figure out how to set the background color for the tool selector
• The Line Tool is currently not available