Blender Git Loki

GPencil: Split Primitive operators and add number of points to Topbar

Now the operators are split to define different default values. This is also required for the future Bezier primitive tools.

This allows to show in the Topbar the number of subdivisions. Before this value was totally hidden and it was number of Edges. The wheelmouse can be used to override the value while running, but does not change the default value.

{F8766270}

All operators share same code.

Also, fixed some bad practices done with Toolbar in python.

Reviewed By: mendio, pepeland

Differential Revision: https://developer.blender.org/D8506