Fixes permission checks for vanilla commands which don't have a
requirement, as well as for namespaced vanilla commands.
== AT ==
public-f com.mojang.brigadier.tree.CommandNode requirement
Datapacks check this on load and are built concurrently. This was breaking them badly due
to race conditions.
Plus, .canUse we want to be safe for async anyways.
Adds AsyncPlayerSendCommandsEvent
- Allows modifying on a per command basis what command data they see.
Adds CommandRegisteredEvent
- Allows manipulating the CommandNode to add more children/metadata for the client
