feat aup field for account creation

1. Add aup field as a checkbox
2. Enable submit button (for account creation) only when aup field is checked
3. Send this flag to rabbitmq agents in the backend

app/static/scripts/function.js

-var check_counter =0;
 function check() { 
   var submitButton = document.getElementById("submit");
-  if ((check_counter+=1)%2) submitButton.disabled = false;
-  else submitButton.disabled = true;
+  let ckbox = document.getElementById('agree');
+  submitButton.disabled = !ckbox.checked;
 };
 
 function displayloading1() {
@@ -20,7 +19,7 @@ function request_account() {
         email: document.getElementById("email").value,
         reason: document.getElementById("reason").value,
         username: document.getElementById("username").value,
-        aup: 1
+        aup: document.getElementById("agree").checked
     })
 }