Make passwords optional when registering a new user

model/src/lib.rs

@@ -56,7 +56,7 @@ pub struct CreateUserRequest {
     pub display_name: Option<String>,
     pub first_name: Option<String>,
     pub last_name: Option<String>,
-    pub password: String,
+    pub password: Option<String>,
 }
 
 #[derive(PartialEq, Eq, Debug, Serialize, Deserialize, Clone, Default)]