Add missing check for keys of data array

The data object that is delivered by the ServiceController via the
rdfauthorinit action contains usually only resource URIs as key. For the
formbuilder branch, this array may contain additional keys that are not URIs
but identifier for additional options. This commit filters out these
special cases.
Merge branch 'feature/sortPropertiesForRDFauthor' into deployment/erm-hd