Resolves dani-garcia/bitwarden_rs#981

* a user without 2fa trying to join a 2fa org will fail, but user gets an email to enable 2fa
* a user disabling 2fa will be removed from 2fa orgs; user gets an email for each org
* an org enabling 2fa policy will remove users without 2fa; users get an email

src/db/models/org_policy.rs

@@ -22,6 +22,7 @@ db_object! {
 
 #[derive(Copy, Clone)]
 #[derive(num_derive::FromPrimitive)]
+#[derive(PartialEq)]
 pub enum OrgPolicyType {
     TwoFactorAuthentication = 0,
     MasterPassword = 1,