Bring two-stage geometry construction into ModuleTest

Older CIT (and I think ASRD) code constructed the module geometry in two steps: the parts which could be learnt form the phi map only, and the rest. The current ModuleTest requires both the phi and the theta maps before geometry gets written. This is not good enough for CIT.

So resurrect the split geometry generation. Pretty simple: phi center and radius.

Note that this ticket will be branched off the cit_freeze branch and merged back on to it, as it cit_freeze were master.