[Intervention] Revocations files optional #4

* makes revocation file upload optional
 * adds overview about revocations to intervention index
 * adds/updates translations

konova/static/css/konova.css

@@ -22,6 +22,10 @@ Declare some basic colours
     color:white;
 }
 
+.rlp-gd-inv{
+    color: var(--rlp-gray-dark);
+}
+
 .rlp-gd-outline{
     border:1px solid var(--rlp-gray-dark);
     color:var(--rlp-gray-dark);