Moved action type into action module.

src/action.rs

@@ -1,7 +1,9 @@
+mod action_type;
 mod message;
 mod query;
 mod user;
 
+pub use action_type::Action;
 pub use crate::document::{definition::DocDef, field::FieldType};
 pub use message::MsgAction;
 pub use query::Query;