Happy 1.17 release day!

• 1.17 Java <-> Bedrock support.
• Spawn Egg Item Conversion has been modified to be more reliable.
• Fixed a bug where inventories would contain air.
• Fixed a bug where flower pots could contain air with an invalid state.
• Fixed a bug where item frames could contain air with an invalid state.
• Fixed ItemFrame rotation between Bedrock -> Java.
• Region files which have no region data are now automatically skipped.