Change Group's measured minimum size computation.
In this change:
If a Group clips content or resizeMode is scale, then measured minimum is zeroed out.
QE Notes: A couple of FxContainer and FxDataContainer tests will fail. Other tests that depend on measured minimum size of a Group with clipContent="true" or resizeMode="scale" will fail and need to be updated.
tests: compile, checkintests, mustella (gumbo/core/..., gumbo/components/FxContainer, gumbo/components/FxDataContainer)