Improve the Pen tool's colinearity and equidistance controls

[0SlowPoke0]

Parly closes #1870

1. C toggles bent vs. colinear handles (instead of the momentary Alt in use now)
2. Alt stops keeping the handles equidistant while pressed, as long as they're currently colinear (otherwise it does nothing) and also covers its exception
3. Preserve collinearity while in GRS mode
4. Closes Use KeyNoRepeat instead of Key to avoid potential user confusion that Tab shouldn't be held in to swap dragged handles #2253
5. When drawing the next segment (mouse is up), Ctrl is down to lock the angle, if you hover over the anchor point, the locked direction changes discord

[Keavon]

!build

[github-actions]

📦 Build Complete for 5109b12
https://5c195c08.graphite.pages.dev

[0HyperCube]

The code seems well structured.