First pass at topas3 ingestion

[ksunden]

I have not yet done test things, though ad hoc tested with teh curves provided in the tests repo

This largely derives from the attune 0.3.1 code.

I have left off saving, largely so that I could ignore fields we don't need for our internal representation (e.g. polarization, comment, etc)
The old version just passed **kwargs and did setattr on extra kwargs. This currently drops them on the floor.

I think there may be some finer details that possibly are represented in the file, but are not handled:

• default values for motors if not used
• there is a field that the code termed "offsets", that we just ignore (it had been passed on in the old code but only ever used for writing to file)
  • This could be some kind of "default position" for if the motor isn't used (though I think it is on a per interaction basis, so not sure that would resolve)
  • Otherwise I don't think the file has default positions, so that behavior is not included here, like it is for topas4, IIRC

Additionally, it currently uses string integer values for motor names, which actually appears to be consistent with attune 0.3.1 behavior, but is negotiable (probably would just be providing a list to the from_topas3 method).
Perhaps we would want to include a handy reference lists for the names of the Wright group OPAs.