germania-sacra: update View Helper argument name for bibliography
rename »dataFields« argument to »data-fields«

to be consistent with »data-format«
edfu: use new data-fields argument name
germania-sacra: use new »data-fields« argument name
Remove »data« action; introduce »data« format instead; adapt templates and links in partials

This seems to be a more consistent approach.
germania-sacra: remove text/json type configuration

we can use the one provided by the extension itself