* Create ValueMapperNode and use it for brightness/contrast
* move spline code into seperate module
* Add GenerateCurvesNode
* add a `LuminanceMut`-trait
* add `lerp` to `Channel`
* Add frontend code to handle the curves widget's inputs
* Rename spline module to curve
* Make messages in CurveInput pass
* Improve curves widget design and fix sizing issue
* Implement proper bezier handling
* Use bezier_rs's intersections function instead of own cubic root solver
* Debounce CurveInput events and change how debouncer works
the first event issued to the debouncer was unneccessarily delayed.
Instead now the debouncer fires it instantaneously but blocks events
that come in until a timeout was reached.
* Make curve editing more user friendly
* Change code to use project terminology
* sample -> manipulator group or manipulator
* marker -> handle
* Fix small documentation mistake in bezier-rs
* Add find_tvalues_for_x function to bezier-rs
also integrate the function into curves node
* Add tests for find_tvalues_for_x in bezier-rs
* Fix formatting
* Revert BrightnessContrastNode changes
* Frontend cleanup
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Co-authored-by: Keavon Chambers <keavon@keavon.com>
Co-authored-by: Dennis Kobert <dennis@kobert.dev>
Keavon Chambers