This PR makes a small improvement to the way we measure distances.
(Often we measure distances multiple times per frame per shape on the
screen). In many cases, we compare a minimum distance. This makes those
checks faster by avoiding a square root.
### Change Type
- [x] `sdk` — Changes the tldraw SDK
- [x] `improvement` — Improving existing features
### Release Notes
- Improve performance of minimum distance checks.
This PR adds a custom tool example, the `Screenshot Tool`.
It demonstrates how a user can create a custom tool together with custom
tool UI.
### Change Type
- [x] `minor` — New feature
### Test Plan
1. Use the screenshot example
### Release Notes
- adds ScreenshotTool custom tool example
- improvements and new exports related to copying and exporting images /
files
- loosens up types around icons and translations
- moving `StateNode.isActive` into an atom
- adding `Editor.path`
Steve Ruiz