Draft: Fix arc offset problem

[Roy-043]

geometry.py:
The findDistance function did not work properly for arcs that crossed the 9 o'clock point.

gui_offset.py:
The ghost of an arc with a start angle that is larger than the end angle would be wrong.

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[berndhahnebach]

do you have a forum link for this? Would you add it?

[Roy-043]

Forum link: https://forum.freecadweb.org/viewtopic.php?f=23&t=59483