Cleanup Namespaces in OAI-DC converted metadata

[sneumann]

Hi,
currently, the OAI-DC that is converted by the json_container2oai_dc.xslt contains some superfluous namespaces:
both

oai4schemas/examples/oai_dc-MIIFHRBUBUHJMC-UHFFFAOYSA-N.1.xml

Line 2 in 5296d8b

xmlns:json="http://nfdi4chem.de/schemas/json-container/1.0/"

and

oai4schemas/examples/oai_dc-MIIFHRBUBUHJMC-UHFFFAOYSA-N.1.xml

Line 3 in 5296d8b

xmlns:map="http://www.w3.org/2005/xpath-functions/map"

would not be needed. They are somehow leftovers of the XSLT

oai4schemas/json_container2oai_dc.xslt

Line 5 in 5296d8b

xmlns:map="http://www.w3.org/2005/xpath-functions/map"

where they are needed during processing of the JSON input with

java -jar /usr/share/java/Saxon-HE-9.9.1.5.jar \
    -s:10.14272-MIIFHRBUBUHJMC-UHFFFAOYSA-N.1.xml  \
    -xsl:json_container2oai_dc.xslt

I think that is mostly cosmetic, but any suggestions and improvements to the XSLT are welcome.
Yours,
Steffen