Fix manual IO setting not saving in filter covers (#3616)

Author: serenibyss

src/main/java/com/gregtechceu/gtceu/common/cover/FluidFilterCover.java

@@ -40,6 +40,7 @@ public class FluidFilterCover extends CoverBehavior implements IUICover {
     @Getter
     protected FilterMode filterMode = FilterMode.FILTER_INSERT;
     private FilteredFluidHandlerWrapper fluidFilterWrapper;
+    @Persisted
     @Setter
     @Getter
     protected ManualIOMode allowFlow = ManualIOMode.DISABLED;

src/main/java/com/gregtechceu/gtceu/common/cover/ItemFilterCover.java

@@ -46,6 +46,7 @@ public class ItemFilterCover extends CoverBehavior implements IUICover {
     @Getter
     protected FilterMode filterMode = FilterMode.FILTER_INSERT;
     private FilteredItemHandlerWrapper itemFilterWrapper;
+    @Persisted
     @Setter
     @Getter
     protected ManualIOMode allowFlow = ManualIOMode.DISABLED;