URL-parsing+rendering part of the first two new convops ready

### Description
This PR implements the parsing of URL plus the rendering in XML and JSON of the first (/v1/contextTypes) of the batch of new convenience operations. A second new conv op is prepared for but not terminated (/v1/contextTypes/{entityType})

What is missing is the mongo part (see '#if 0' in serviceRoutines).

I agree. Any XML/JSON sample in code comments could become obsolete (note that no other .cpp file in this library include such samples). The place for XML/JSON fragments should be the .test files.