PCK Resource Pack pck-test-4

Fix wing trim transparency backgrounds, add pck:eternal_elytra equipment asset, and validate wing trim textures during pack builds.

PCK Resource Pack pck-test-3

Fixes silence wing trim transparency for Eternal Elytra.

PCK Resource Pack pck-test-2

Includes Eternal Elytra wing trims and baby dragon parrot texture.

PCK test resource pack 1

Adds the PCK test item texture based on the Box5789 GitHub avatar.