This adds the `Jitter` draw tool option in the randomize panel.
To make this work in combination with the active smoothing, the jitter of the positions is applied
after active smoothing as an effect on top.
This means that the active smooth will not smooth the jittered points.
In addition, it is also now allowed to raise the `Jitter` factor above 1 for a more extreme effect.
Note: The jittering worked a bit differently in GPv2 (probably because of a bug). In GPv3 we compute the cotangent using the smoothed stroke direction (over time), which is a lot more acurate then using the previous and current position for the direction.
Pull Request: https://projects.blender.org/blender/blender/pulls/123680
9ffb277e01