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.
we split it up before we realized it was non-destructively backwards compatible because we were worried about how long it was going to take and had to revert.

for this one is that also true? i think for any migration like this we want to understand:

1. whether the new structure works in the old code or not
2. whether the old structure works in the new code or not

if either of these are true then i might go back on my idea that using south data migrations was a good idea. if 1 is true you can run a management command before deploy, if 2 is true you can do it after deploy, and if both are true you can do it whenever.

i think we should only want to use south when both 1 and 2 are not true, and we do want to do the work "in between" the deploy.