JEXL3: Look into JEXL's updated 'contains' support

[jwomeara]

JEXL updated the default arithmetic to support comparisons against sets of values. We should look into this and see if it is suitable for our needs. If so, we might be able to remove our custom functional set logic.

[cogross]

Was fighting with getting everything rewired to use JEXL3.3 instead of 2.1.1. Saw that a new jexl3 branch popped in. Running from that, I have determined that DelegatingArithmetic.contains() and EdgePreconditionArithmetic.contains() can be removed.
I can make a branch based off jexl3 and remove those 2 functions, or it could just be a part of the new branch. Thoughts?

[jwomeara]

We don't want to remove contains. The ticket is to move away from our functional set usage and rely on contains instead. This work shouldn't be done at all until the jexl3 branch is merged, so I would direct all of your comments there in the form of a review.

[cogross]

Okay. Wasn't sure which set comparisons to use then. I'll look over that branch when it's done.