MaimMim Man in the middle minetest interceptor

- prototype
- between client and server, allow to capture all exchanges and potentially change them
- created to capture server maps in laby
- first test get only MapBlock, support version serialization version 28
  - prepartion for 29 with zstd but untested.

# Conflicts:
#	fetch_dependencies.sh

java/org/artisanlogiciel/games/minetest/net/ConnectionEventPtr.java

@@ -0,0 +1,4 @@
+package org.artisanlogiciel.games.minetest.net;
+
+public class ConnectionEventPtr {
+}