Adds Dynmap integration

This adds Dynmap integration for displaying Stargates in Dynmap
API version is changed back to 1.18 as 1.19 is still kind of new
Version is now 0.9.4.1

src/main/java/net/knarcraft/stargate/portal/PortalRegistry.java

@@ -1,6 +1,7 @@
 package net.knarcraft.stargate.portal;
 
 import net.knarcraft.stargate.Stargate;
+import net.knarcraft.stargate.config.DynmapManager;
 import net.knarcraft.stargate.container.BlockLocation;
 import net.knarcraft.stargate.utility.PortalFileHelper;
 import org.bukkit.World;
@@ -224,6 +225,7 @@ public class PortalRegistry {
 
         PortalFileHelper.saveAllPortals(portal.getWorld());
         portal.setRegistered(false);
+        DynmapManager.removePortalMarker(portal);
     }
 
     /**
@@ -289,6 +291,7 @@ public class PortalRegistry {
 
         allPortals.add(portal);
         portal.setRegistered(true);
+        DynmapManager.addPortalMarker(portal);
     }
 
 }