Make suggest gemming shared & add for hunter

[1337LutZ]

Tried to make the suggest option more generic to be more easily implemented by other classes.
(I know the feature in general was/is pretty tailored towards ArP users that rely on quite "flat" caps)

• Moved all auto gem code to shared folder
• Incorporated existing spec (Feral/Warrior) specific logic
• Added Hunter (need a check on this but it seems to work pretty well vs existing BIS sets)
• Tweaked Warrior gemming to allow for gemming ArP in yellow sockets

[hululula]

Worked with 1337LutZ to verify the gemming configurations and it looks good to me now. (Monsterik in discord)