revert Fix: weight and vertex paint radial symmetry wrong with mirror
Was causing #121155, will check again on Monday
Both vertexpaint and weightpaint would only apply all of radial symmetry
for the "initial stroke".
When going over the combinations of symmetry axis, some of radial
symmetry would be skipped, e.g. when mirroring from right to left with
`Mirror X` turned ON, a dab on the right would have radial symmetry from
that point, and an additional dab on the left from mirroring (but the
mirrored dab would not have radial symmetry on its own).
This does not lead to symmetric results at all, sculptmode also does not
behave that way (there, radial symmetry is performed on the mirror axis
as well).
Now do the same thing as in sculptmode to get symmetric results when
using mirror and radial symmetry together.
Also use the utility function to skip invalid symmetry iterations.
Stumbled over this when looking into #120843
Pull Request: https://projects.blender.org/blender/blender/pulls/120931
0bf4568abd