division_io.py parliament update should give a count of just the changed items

[ajparsons]

update-from-commons-votes says it’s updating 777 rows each time, presumably it should be doing 0 if I run it again, or will it always ‘update’ ones at same level I guess

Always updates at the same level (and we want this if the external description changes) - but we want a more helpful description of what’s changed - ideally we weed out any there’s going to be no difference for (given we can know the titles before and after) - but a bit fiddly to also make work for manual updates to yes_text etc.