Add more script scaling options

[Yoooi0]

Non-uniform normalize scale type, interpolate keyframes 0%-100% towards edges (how does this work with custom default value axes, like 25%)
Linear scale up/down of values (current scaling)
Uniform normalize to 0%-100%, would only work if all keyframe values are <100 and >0 (add ability scale tops/bottoms only?)
Normalize towards moving average of tops/bottoms
Normalize based on move length? Minimum/Maximum %
Speed limit based scaling (towards top, towards bottom, towards side closer to 0%/100%)
Other scaling methods?

Prescale keyframe collection when loading (pass to script readers as options class) or do in main loop?
Rework as a script postprocessors, work on keyframes from script readers, can add other options like invert (interpolate? RDP simplify?)

Add scale preview