Various blocks don't display their metadata in the F3 screen

• Comparators only show their internal damage value, not the values of their specific attributes (direction, subtraction, or whether or not they are powered)
• Blocks with facing values (including hoppers and end portal frames)
• Flowers
• Quartz
• Anvils
• Buttons
• Beds
• Rail (facing and whether or not they are powered)
• Leaves
• Slabs
• Wool and hardened clay and carpets
• Nether portal blocks
• Standing signs and torches