MultiVOMetadata doubling VO identifier

[andresailer]

It happens that the metadata key has twice appended (for example in the Transformation.InputDataAgent)

DIRAC/src/DIRAC/DataManagementSystem/DB/FileCatalogComponents/DirectoryMetadata/MultiVODirectoryMetadata.py

Line 23 in 4886513

return meta + _getMetaNameSuffix(credDict) if meta not in MetaQuery.FILE_STANDARD_METAKEYS else meta

Should

1. Prevent the creation of meta data keys with ___ inside
2. Only append ___<vo> if it hasn't been appended yet

cc. @marianne013 @martynia

[martynia]

@andresailer could you post medatadata commands you used with @marianne013 to add to the catalog, so I could reproduce the issue ?

[andresailer]

https://dirac.readthedocs.io/en/latest/AdministratorGuide/Tutorials/dmsWithTs.html#using-metadata-queries-to-add-files-to-transformations

[martynia]

Fix proposal here: #7708