Bugfix update + Upstream (Pufferfish)

Closes #11

patches/server/0017-Make-a-field-final.patch

@@ -0,0 +1,21 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: foss-mc <69294560+foss-mc@users.noreply.github.com>
+Date: Thu, 1 Jul 2021 12:11:49 +0000
+Subject: [PATCH] Make a field final
+
+Original code by PatinaMC, licensed under GNU General Public License v3.0
+You can find the original code on https://github.com/PatinaMC/Patina
+
+diff --git a/src/main/java/net/minecraft/commands/CommandSourceStack.java b/src/main/java/net/minecraft/commands/CommandSourceStack.java
+index 098182d2426a25cef0bc285356bc346db0af8172..050f73a4f2dd53d6e36fc4faa803bf1a184af54b 100644
+--- a/src/main/java/net/minecraft/commands/CommandSourceStack.java
++++ b/src/main/java/net/minecraft/commands/CommandSourceStack.java
+@@ -56,7 +56,7 @@ public class CommandSourceStack implements SharedSuggestionProvider, com.destroy
+     private final ResultConsumer<CommandSourceStack> consumer;
+     private final EntityAnchorArgument.Anchor anchor;
+     private final Vec2 rotation;
+-    public java.util.Map<Thread, CommandNode> currentCommand = new java.util.concurrent.ConcurrentHashMap<>(); // CraftBukkit // Paper
++    public final java.util.Map<Thread, CommandNode> currentCommand = new java.util.concurrent.ConcurrentHashMap<>(); // CraftBukkit // Paper // Patina - make a field final
+ 
+     public CommandSourceStack(CommandSource output, Vec3 pos, Vec2 rot, ServerLevel world, int level, String name, Component displayName, MinecraftServer server, @Nullable Entity entity) {
+         this(output, pos, rot, world, level, name, displayName, server, entity, false, (commandcontext, flag, j) -> {