Fix Head Error and new flowers

What's new:

• Heads display correctly on 1.21 again (Closes #56)
• Added Pale Oak Leaves
• Added Pale Oak Sapling
• Added Pale Hanging Moss
• Added Pale Moss Carpet
• Added Pale Moss Block
• Added Hanging Roots
• Added Moss Carpet

Full Changelog: 1.2.4...1.2.5