Uncut gem feedback

Some additions:
- Uncut gems of same level and type (skill / support / spirit) should stack to 10/20 in one item slot. Currently if you keep them they can occupy a whole stash tab when you reach endgame.
- Would be nice if there was a system to convert X uncut gems of separate type to one uncut gem of other type. So for example - if you have 20 skill gems of level 14 and can't get a drop of spirit gem level 14 to finally get access to some highest tier aura you could exchange X uncut skill gems for 1 uncut spirit gem of similar level.