merge from 2.6 branch: add support for EML 2.1.1 in OAI-PMH provider. https://projects.ecoinformatics.org/ecoinfo/issues/7009
merge from 2.6 branch: add support for EML 2.1.1 in OAI-PMH provider. https://projects.ecoinformatics.org/ecoinfo/issues/7009