Added an error code for email already verified

See parse-community/parse-server##7740

This PR adds a new error code when users requestEmailVerification for verified email, now the parse server sends the OTHER_CAUSE error code and it needs A better error code instead of -1 and should have a message instead of stack property.

src/ParseError.js

@@ -433,6 +433,15 @@ ParseError.EMAIL_MISSING = 204;
  */
 ParseError.EMAIL_NOT_FOUND = 205;
 
+/**
+ * Error code indicating that the email has already been verified and can not be verified again.
+ *
+ * @property {number} EMAIL_ALREADYـVERIFIED
+ * @static
+ */
+ParseError.EMAIL_ALREADYـVERIFIED = 212;
+
+
 /**
  * Error code indicating that a user object without a valid session could
  * not be altered.