Support String UUID's in old player skulls

Should fix remaining skull issues for people with unconverted old skulls.

Fixes #3734

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

@@ -7,6 +7,22 @@ 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/GameProfileSerializer.java b/src/main/java/net/minecraft/server/GameProfileSerializer.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/GameProfileSerializer.java
++++ b/src/main/java/net/minecraft/server/GameProfileSerializer.java
+@@ -0,0 +0,0 @@ public final class GameProfileSerializer {
+             s = nbttagcompound.getString("Name");
+         }
+ 
++        // Paper start - support string UUID's
++        if (nbttagcompound.hasKeyOfType("Id", 8)) {
++            uuid = UUID.fromString(nbttagcompound.getString("Id"));
++        }
++        // Paper end
+         if (nbttagcompound.b("Id")) {
+             uuid = nbttagcompound.a("Id");
+         }
 diff --git a/src/main/java/net/minecraft/server/NBTTagCompound.java b/src/main/java/net/minecraft/server/NBTTagCompound.java
 index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
 --- a/src/main/java/net/minecraft/server/NBTTagCompound.java