Split CAFMaker into record-making and CAF-making parts

[cjbacchus]

CAFMaker does (at least) two things

1. Summarizes art level information into StandardRecord objects
2. Writes those objects to an output TFile (the CAF)

This issue is to split the two parts into separate modules (StandardRecordMaker and CAFMaker?) that would usually run one after the other, reproducing the current behaviour, but also enabling some other modes of operation.

The records from 1. would be communicated to 2. by writing them into the art record. That is already happening, they are simply immediately dropped because we don't configure an art output file.

Probably this is a little more complicated than I have made it sound, due to things done at the run/subrun level (I think 1. should write an SRGlobal product to be written by 2. for example), metadata, etc. The only way to find all these intertwined places is to try and separate them. The sooner this is done, the less untangling there will be to do.

[wesketchum]

sorry, probably not right to close....right @cjbackhouse ?