Refactor: libcrmcommon: new convenience function pcmk__is_up_action()

The new function checks for start, promote, or migrate_from.

Some of the callers previously did not check for one or another of the actions,
but they were not reachable with those, so nothing really changes, and this is
logically consistent.

The previous code incorrectly used a case-insensitive comparison. The
new code is case-sensitive.