ENH: GMVABORT has become obsolete, relying on GMVERROR now

     gmvread.c from VisItBridge repository has been patched such that the
     separate return code GMVABORT added a few revision back is not required
     any more
Adding tests to avoid regressions for #13958

Simplified CMake logic while at it
Merge topic 'gmv_contribution_integration' into next

f9ade3c Adding tests to avoid regressions for #13958
0f540c0 ENH: GMVABORT has become obsolete, relying on GMVERROR now