No user visible changes expected.
Used in the asset shelf branch, see #104831.
Adds:
- Custom callback to return a quick label. This is useful when a label
tooltip should be displayed even when there is no button string set.
E.g. in the asset shelf with "Show Names" disabled.
- A flag to force enable quick label tooltips, since the internal checks
are rather ad-hoc and it's useful to be able to just override them.
Julian Eisel