Refactor users management

* Shard `src/data/user.rs` into two different files
  * One for user data structure (same file)
  * One for user manipulation (new file: `user_file_entity.rs`)
* Isolate password hashing and verification

src/actors/users_actor.rs

@@ -26,6 +26,10 @@ pub struct GetUserRequest(pub UserID);
 #[derive(Debug)]
 pub struct GetUserResult(pub Option<User>);
 
+#[derive(Message)]
+#[rtype(result = "bool")]
+pub struct VerifyUserPasswordRequest(pub UserID, pub String);
+
 #[derive(Message)]
 #[rtype(FindUserByUsernameResult)]
 pub struct FindUserByUsername(pub String);
@@ -85,7 +89,7 @@ impl Handler<LoginRequest> for UsersActor {
         match self.manager.find_by_username_or_email(&msg.login) {
             None => MessageResult(LoginResult::AccountNotFound),
             Some(user) => {
-                if !user.verify_password(&msg.password) {
+                if !self.manager.verify_user_password(&user.uid, &msg.password) {
                     return MessageResult(LoginResult::InvalidPassword);
                 }
 
@@ -132,6 +136,14 @@ impl Handler<GetUserRequest> for UsersActor {
     }
 }
 
+impl Handler<VerifyUserPasswordRequest> for UsersActor {
+    type Result = <VerifyUserPasswordRequest as actix::Message>::Result;
+
+    fn handle(&mut self, msg: VerifyUserPasswordRequest, _ctx: &mut Self::Context) -> Self::Result {
+        self.manager.verify_user_password(&msg.0, &msg.1)
+    }
+}
+
 impl Handler<FindUserByUsername> for UsersActor {
     type Result = MessageResult<FindUserByUsername>;