Add DeferredHolderCommon#getHolder

Author: rubensworks

loader-common/src/main/java/org/cyclops/cyclopscore/config/DeferredHolderCommon.java

@@ -175,6 +175,15 @@ public ResourceKey<R> getKey() {
         return this.key;
     }
 
+    // TODO: Added as workaround for not implementing Holder directly. Not sure yet if we want this permanently.
+    public Holder<R> getHolder() {
+        bind(true);
+        if (holder == null) {
+            throw new IllegalStateException("Trying to access unbound holder: " + this.key);
+        }
+        return holder;
+    }
+
     @Override
     public boolean equals(Object obj) {
         if (this == obj) return true;