[Part] fix angular measurement
[Part] fix angular measurement

the arrow heads are much too large so that the feature use quite useless

The PR fixes this to make the arrow heads as large as for linear dimensions
It also slightly increase the arrow head size since.

Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master,Fat-Zer/FreeCAD_sf_master