This PR:
1. Adds a `renderingOnly` option to the `Editor.getShapeAtPoint` method.
When true, the method will only hit test against rendering shapes
(shapes that are inside of the current `renderingBounds`) rather than
all shapes on the canvas.
2. Includes some low level improvements to the way that edges find their
nearest point.
3. Includes a fix to circle geometry that could produce NaN values
### Change Type
- [x] `minor` — New feature
### Test Plan
1. Check whether hovering shapes still works as you would expect.
- [x] Unit Tests
### Release Notes
- Improve perf for hovering shapes / shape hit tests
