general: test fixes

• BibDocFile: Fixes list_bibdocs(doctype) which was looking for the relation type instead of the doctype of the attached bibdocs.

• For tests, ignores all records that have a master format different from "marc".

• DocExtract: fixes record tests

• Checks that bibrec rows are not missing where running tests.

• BibFormat: fixes bibformat unit tests

• Make the french translation dynamic in test which means the tests will pass when translations are not installed.

• MiscUtils: fixes import in plotextractor tests

• Fixes dateutils tests

• Makes the test work when language translations are not installed.

Signed-off-by: Alessio Deiana <alessio.deiana@cern.ch>
Tested-by: Samuele Kaplun <samuele.kaplun@cern.ch>