Suggestion: Weapon set support gems

In addition to needing weapon lock, a big issue with weapon swap is if we want to have one set for boss and one for clear (for example), there is a lot of overlap in how supports are used but not total overlap. This means even if we use a second version of the skill gem, we can't optimally configure it to swap supports in a nice way automatically. Instead we'd have to manually move them over.

It would be nice if we could have a skill use two different support gem layouts, each tied to a different weapon set, without it being a different skill gem. Naturally, the rule about only using a support gem once would be *per* weapon set.

The idea is that I could, for example, socket Rolling Slam with Magnified Effect, Brutality, and Heft in one weapon set, but swap it to Concentrated, Brutality, and Heft in the other for punishing a stun on a boss. And I would be able to do this with only one Rolling Slam skill gem equipped and without manually swapping supports.

This is also useful for things like disabling the Chain support gem on a boss.