Migrate DWARFVerifier tests to lit-based yaml instead of gtest with embedded yaml

Improves maintainability (edit/modify the tests without recompiling) and
error messages (previously the failure would be a gtest failure
mentioning nothing of the input or desired text) and the option to
improve tests with more checks.

(maybe these tests shouldn't all be in separate files - we could
probably have DWARF yaml that contains multiple errors while still being
fairly maintainable - the various invalid offsets (ref_addr, rnglists,
ranges, etc) could probably be all in one test, but for the simple sake
of the migration I just did the mechanical thing here)