A couple of features for better planet modding (#8558)

* Planet item whitelist

* allowLaunchToNumbered for planets

* Update core/src/mindustry/type/Planet.java

* Update core/src/mindustry/type/Planet.java

---------

Co-authored-by: Anuken <arnukren@gmail.com>

core/src/mindustry/content/Planets.java

@@ -68,6 +68,9 @@ public class Planets{
             hiddenItems.addAll(Items.serpuloItems).removeAll(Items.erekirItems);
             enemyBuildSpeedMultiplier = 0.4f;
 
+            //TODO disallowed for now
+            allowLaunchToNumbered = false;
+
             //TODO SHOULD there be lighting?
             updateLighting = false;