Refactor Module into a single record type and fix system globals (#1383)

src/main/java/carpet/script/ScriptServer.java

@@ -0,0 +1,11 @@
+package carpet.script;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import carpet.script.value.Value;
+
+// WIP
+public class ScriptServer {
+    public final Map<Value, Value> systemGlobals = new ConcurrentHashMap<>();
+}