Graphing Configuration for 2.17

These changes adjust the graph configuration modal slightly to support the additions and changes to the graph configuration options that will be introduced in 2.17. There is also a migration here to support the change of `x-lable-count` and `y-label-count` to `x-labels` and `y-labels`. There should only be a handful of apps that need to be altered.

**DO NOT MERGE** until 2.17 is released.
cool, thanks for the the thorough writeup.

yeah i think your plan is what i would suggest. the main reason is that doing it during the deploy has some negative side effects. namely:

1. celery gets stopped for migrations so it is down the whole time the migration is running unless someone goes in and starts it back ukp.
2. at the time the migration is run, the new code has been deployed to all machines but is not supposed to be running. however, if a gunicorn process restarts (which they do after a certain number of requests) it will start running off the new code, which can lead to some issues. this can also be problematic if there were static files changes because the staticfiles build script runs after migrate.

so generally the "automatic" thing ends up causing problems during the deploy anyways and sometimes site unreliability so the manual step is actually less painful.