Improve tools

[0HyperCube]

Closes #3028
Depends on #2983

Improvements:

• Separate some of the functionality of the select tool into separate files (only partially done).

Fixes:

• alt duplicating in the select tool sometimes applies an offset.
• update_hints didn't have access to the tool_data so was implemented in a hacky way in the select tool and path tool
• Offsets when drawing on non-origin artboard in:
  • line tool
  • freehand tool
  • pen tool
  • text tool
• Gradient tool double click insert stop Cannot insert new point in gradient with double click #3028

[0HyperCube]

I don't think it is worth pursuing this approach any more. The tools already work at least half of the time.