Fix #39 and JDK 21 Upgrade an Grid Square Coloring

* Fixed Map: leaflet rendering in Java 21 Webview (disabling 3D in leaflet)

* Added grid square coloring function and fixed bug of message categorizing after entering the chat and not selected a chatmember

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Authored-by: Marc Froehlich <praktimarc@gmail.com>

src/main/java/module-info.java

@@ -18,4 +18,4 @@ module praktiKST {
 
 
 	opens kst4contest.view.map to javafx.web;
-}
+}