Changes to edit mode mesh overlays, use hue shift instead of color
fading/darkening for selection mode visual differentiation, and some
theme changes to improve the display of mesh edges and faces with good
selection visibility.
- Removed "edge" toggle from edit mode overlays panel.
- No longer halves the edge and face alpha depending on selection mode.
Half the face alpha in wire-frame mode. For better visibility on most
themes.
Ref !111431