SyncFlags: move into sync package

They are currently unused, so should be fine.

Author: greenrobot-team

objectbox-java/src/main/java/io/objectbox/model/SyncFlags.java renamed to objectbox-java/src/main/java/io/objectbox/sync/SyncFlags.java

@@ -16,7 +16,7 @@
 
 // automatically generated by the FlatBuffers compiler, do not modify
 
-package io.objectbox.model;
+package io.objectbox.sync;
 
 /**
  * Flags to adjust sync behavior like additional logging.