Run the tests under ASAN to detect potential problems.
Also enable optimizations for the universal build (overriding
--disable-optimise used by default) to check that there are no problems
with building wxWidgets for real production use.
Don't run 8 builds for all combinations of arch/debug/C++ dialect but
just a few of them covering all of the possibilities.
Also add a static universal build which is what is commonly used for
distributing software using wxWidgets under Mac.
Call this file consistently with the other CI files and also ignore all
of the other files in each workflow to avoid unnecessary rebuilds.
Finally, remove a leftover mention of Travis file which doesn't exist
any longer.
