Brigadier Mojang API

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

paper-server/patches/sources/com/mojang/brigadier/exceptions/CommandSyntaxException.java.patch

@@ -0,0 +1,23 @@
+--- a/com/mojang/brigadier/exceptions/CommandSyntaxException.java
++++ b/com/mojang/brigadier/exceptions/CommandSyntaxException.java
+@@ -5,7 +5,7 @@
+ 
+ import com.mojang.brigadier.Message;
+ 
+-public class CommandSyntaxException extends Exception {
++public class CommandSyntaxException extends Exception implements net.kyori.adventure.util.ComponentMessageThrowable { // Paper - Brigadier API
+     public static final int CONTEXT_AMOUNT = 10;
+     public static boolean ENABLE_COMMAND_STACK_TRACES = true;
+     public static BuiltInExceptionProvider BUILT_IN_EXCEPTIONS = new BuiltInExceptions();
+@@ -73,4 +73,11 @@
+     public int getCursor() {
+         return cursor;
+     }
++
++    // Paper start - Brigadier API
++    @Override
++    public @org.jetbrains.annotations.Nullable net.kyori.adventure.text.Component componentMessage() {
++        return io.papermc.paper.brigadier.PaperBrigadier.componentFromMessage(this.message);
++    }
++    // Paper end - Brigadier API
+ }