Implement V2 key rotation support

src/db/models/organization.rs

@@ -54,6 +54,8 @@ pub struct Membership {
     pub atype: i32,
     pub reset_password_key: Option<String>,
     pub external_id: Option<String>,
+    /// The user's v2 upgrade token, for the org to unwrap the v2 user key after an upgrade. Opaque to us.
+    pub v2_upgrade_token: Option<String>,
 }
 
 #[derive(Identifiable, Queryable, Insertable, AsChangeset)]
@@ -271,6 +273,7 @@ impl Membership {
             atype: MembershipType::User as i32,
             reset_password_key: None,
             external_id: None,
+            v2_upgrade_token: None,
         }
     }