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'm afraid that I'm getting errors in my system dure to random attribute ordering:

```
-----  Convenience2 contextEntityTypes test  -----
(convenience2_info_contextEntityTypes.test) output not as expected
VALIDATION ERROR: input line:
             <name>pressure</name>
does not match ref line:
             <name>temperature</name>
```

Thus we would need the `#UNSORT_BEGIN` / `#UNSORT_END` marks as we discussed yesterday...