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/mail.rs

@@ -179,6 +179,22 @@ pub fn send_welcome_must_verify(address: &str, uuid: &str) -> EmptyResult {
     send_email(address, &subject, body_html, body_text)
 }
 
+pub fn send_2fa_removed_from_org(
+    address: &str,
+    org_name: &str,
+) -> EmptyResult {
+
+    let (subject, body_html, body_text) = get_text(
+        "email/send_2fa_removed_from_org",
+        json!({
+            "url": CONFIG.domain(),
+            "org_name": org_name,
+        }),
+    )?;
+
+    send_email(address, &subject, body_html, body_text)
+}
+
 pub fn send_invite(
     address: &str,
     uuid: &str,