Improve old UUID support, clean up old legacy keys.

If we set a UUID to new format, need to make sure old format doesn't
exist anymore. Additionally, ensure if new format exists, we prefer it over old.

Spigot-Server-Patches/0527-Support-old-UUID-format-for-NBT.patch

@@ -8,15 +8,28 @@ We have stored UUID in plenty of places that did not get DFU'd
 So just look for old format and load it if it exists.
 
 diff --git a/src/main/java/net/minecraft/server/NBTTagCompound.java b/src/main/java/net/minecraft/server/NBTTagCompound.java
-index f608b35502890650adfc1df35e0794471f57ecbc..74a8418b72f97a8956857a46fb06251602ad30e3 100644
+index f608b35502890650adfc1df35e0794471f57ecbc..436f40bcd7817bedde4f6570c7c47dba7ff7034f 100644
 --- a/src/main/java/net/minecraft/server/NBTTagCompound.java
 +++ b/src/main/java/net/minecraft/server/NBTTagCompound.java
-@@ -142,11 +142,21 @@ public class NBTTagCompound implements NBTBase {
+@@ -135,6 +135,12 @@ public class NBTTagCompound implements NBTBase {
+ 
+     public void setUUID(String prefix, UUID uuid) { a(prefix, uuid); } // Paper - OBFHELPER
+     public void a(String s, UUID uuid) {
++        // Paper start - support old format
++        if (this.hasKeyOfType(s + "Most", 99) && this.hasKeyOfType(s + "Least", 99)) {
++            this.map.remove(s + "Most");
++            this.map.remove(s + "Least");
++        }
++        // Paper end
+         this.map.put(s, GameProfileSerializer.a(uuid));
+     }
+ 
+@@ -142,11 +148,21 @@ public class NBTTagCompound implements NBTBase {
      @Nullable public UUID getUUID(String prefix) { return a(prefix); } // Paper - OBFHELPER
      @Nullable
      public UUID a(String s) {
 +        // Paper start - support old format
-+        if (hasKey(s + "Least") && hasKey(s + "Most")) {
++        if (!hasKeyOfType(s, 11) && this.hasKeyOfType(s + "Most", 99) && this.hasKeyOfType(s + "Least", 99)) {
 +            return new UUID(this.getLong(s + "Most"), this.getLong(s + "Least"));
 +        }
 +        // Paper end
@@ -26,7 +39,7 @@ index f608b35502890650adfc1df35e0794471f57ecbc..74a8418b72f97a8956857a46fb062516
      public final boolean hasUUID(String s) { return this.b(s); } // Paper - OBFHELPER
      public boolean b(String s) {
 +        // Paper start - support old format
-+        if (hasKey(s + "Least") && hasKey(s + "Most")) {
++        if (this.hasKeyOfType(s + "Most", 99) && this.hasKeyOfType(s + "Least", 99)) {
 +            return true;
 +        }
 +        // Paper end