[Feature] Add ability to "pin" builds during a search to compare

[fribbels]

Motivation

If I'm trying to build a character and there's multiple builds I'm considering, it would be nice to be able to pin them all in one place so they're easy to compare

Objective

Add a couple buttons to the optimizer tab to be able to pin a selected build to the top, and also clear pinned builds (but keep the currently-equipped pin)

[fribbels]

We should be able to just attach relic ids to the simulations