Fritz's RPG: Black Crown 0.2.0

- Adds the Durnan, the Ashen Smith boss prototype.
- Three combat phases controlled by datapack functions.
- Adds Ashen Core, Ashen Armor Fragment and Durnan's Trophy.
- Adds boss bar, custom loot table and defeat advancement.
- Uses a Piglin Brute base for stable Epic Fight compatibility during prototype testing.
- Summon with: /function fritzsrpg:bosses/summon_durnan
