Fix concurrency issues in DataFixers

We are seeing issues with DataFixers being not thread safe in async chunks
and even in some spigot packet sending code.

There are a few more global objects that are mutated that need to
be synchronized to be safe for use over multiple threads.

There may be more cases, but these are extremely obvious ones.

scripts/importmcdev.sh

@@ -84,7 +84,11 @@ for f in $files; do
 done
 
 # Import Libraries - these must always be mapped manually, no automatic stuff
-
+#             group       lib             prefix                    files
+importLibrary com.mojang datafixerupper com/mojang/datafixers \
+    schemas/Schema.java \
+    DataFixerUpper.java \
+    types/families/RecursiveTypeFamily.java
 
 
 # Temporarily add new NMS dev imports here before you run paper patch