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 two first of the batch of new convenience operations.
What is missing is the mongo part (see '#if 0' in serviceRoutines).

Intead of using this "typesFound", let's reuse the same approch that for pagination in other kind of queries (i.e. using StatusCode with details with "Count: 4" when `?details=on` is included in the URL).