Tag datagen: update raw ores; add dusts + nuggets

[unilock]

This PR mainly updates MythicItemDataProvider:

• #mythicmetals:raw_ores is now added to #c:raw_ores, just as #mythicmetals:ingots is added to #c:ingots
• Tags for Dusts and Nuggets are now generated
  • As these can be disabled in the mod config, each tag entry is marked as optional (not required by default)
  • #mythicmetals:dusts is added to #c:dusts and #mythicmetals:nuggets is added to #c:nuggets as well
  • Copper Dust and Nuggets have to be handled separately as they are not included in the ItemSet array returned by ReflectionUtils, and they're not registered during datagen for some reason? (unlike all other Dusts and Nuggets)
• The JSON files for the resulting #c:dusts, #c:nuggets, and #c:raw_ores look a little broken, but so does #c:ingots so I guess it's fine?

ItemSet has been updated as well, as tag injection for nuggets is no longer necessary.

This fully fixes #183.

[Noaaan]

If I recall correctly I did squash some bugs related to datagen when porting. Multiple entries of the same tag while tag nesting are functional, but technically incorrect (ugly). It happens since there is no collision checks during the datagen (correct handling is only adding it once). I am slightly worried with nesting mythicmetals:dusts within c:dusts. Does this not throw a warning if the former is empty? (Which could happen if disabled)

[unilock]

I am slightly worried with nesting mythicmetals:dusts within c:dusts. Does this not throw a warning if the former is empty? (Which could happen if disabled)

It does not. #mythicmetals:dusts can still be referenced in-game (e.g. in REI's "tag viewer" category), but is simply empty.

[Noaaan]

Ok thats great. From a glance it looks fine. Will give a better review ASAP 👍