Doku's RPG

Added:

• dried ghast
• happy ghast
• harness item
• several gui elements
• glint particle

Other Changes and Notes:

• fixed an issue with the gold, iron, and netherite leggings

• removed a few files related to backward compatibility without losing functionality

• updated entity.fsh core shader file to fix transparency on paintings.

• I am currently not planning on making a custom texture for the ghast harness, though I might make some slight changes to it in a future update.