Extract governor states into a better organizing object

[JunAishima]

Perhaps use an enum or something. The hard-coded, capitalized state names are all over LSDC, and it would be better to have them consolidated into a single place.

This will enable something like #369 for state checking ("state_SA", etc.) to be easier to calculate and be used in many places.

[vshekar]

I've been using it in albula management code:

lsdc/gui/albula/controller.py

Line 45 in 969ef44

class GovState(Enum):

Perhaps its time to move it to gov_lib