Added mouse drag selection modes

[FastestMolasses]

Description

There are 3 different selection modes that editors typically have when clicking and dragging the mouse.

1. Character - simple click and drag to select by character
2. Word - double click a word and then drag to start selecting by word ranges
3. Line - triple click and drag to start selecting by entire lines

This PR tracks and implements the different selection mode behaviors.

Related Issues

Closes #74

Checklist

• I read and understood the contributing guide as well as the code of conduct
• The issues this PR addresses are related to each other
• My changes generate no new warnings
• My code builds and runs on my machine
• My changes are all related to the related issue above
• I documented my code

Screenshots

Character selection (default behavior, unchanged)

Screen.Recording.2025-03-30.at.6.12.36.AM.mov

Double click for word selection

Screen.Recording.2025-03-30.at.6.14.26.AM.mov

Triple click for line selection

output.mov

[thecoolwinter]

Works like a charm, can I just request a small re-arrange? I dislike this new enum being in the TextSelection file (since that's a specific struct type and is unrelated).

Could we rename it to CursorSelectionMode and move it to it's own file?

[FastestMolasses]

Updated!

[thecoolwinter]

Awesome!