feat: answer received form submissions by mail

src/Config/EmailTextKey.php

@@ -12,6 +12,8 @@ enum EmailTextKey: string
 {
     case APPLICATION_ACCEPTED = 'application_accepted';
     case APPLICATION_ACCEPTED_NO_CONTRACT = 'application_accepted_no_contract';
+    case APPLICATION_FORM_FOLLOW_UP = 'application_form_follow_up';
+    case APPLICATION_FORM_RECEIVED = 'application_form_received';
     case APPLICATION_REJECTED = 'application_rejected';
     case ASSIGNMENT_CALLED_OFF = 'assignment_called_off';
     case DISPOSITION_CALLED_OFF = 'disposition_called_off';