TT#177851 BillingNetworks close button (back) target selection

* target selection for chained routes in BillingNetworks is now
  performed based on the account that $c->stash->{close_target}
  can be already set, and it's used if defined instead of the
  explicit target
* add NGCP::Panel::Utils::Navigation::select_back_target()
* NGCP::Panel::Utils::Navigation::back_or() now uses internally
  select_back_target()

Change-Id: If6ca47a776896db48955a04f544731dc87c59aa1

lib/NGCP/Panel/Controller/Network.pm

@@ -182,7 +182,8 @@ sub edit :Chained('base') :PathPart('edit') :Args(0) {
         params => $c->request->params,
         item => $params,
     );
-    if($posted && $form->validated) {
+
+    if ($posted && $form->validated) {
 
         try {
             $c->model('DB')->schema->txn_do( sub {
@@ -212,8 +213,13 @@ sub edit :Chained('base') :PathPart('edit') :Args(0) {
 
     }
 
+    my $target =
+        NGCP::Panel::Utils::Navigation::select_back_target(
+            $c, $c->uri_for('/network')
+    );
+
     $c->stash(
-        close_target => $c->uri_for,
+        close_target => $target,
         edit_flag => 1,
         form => $form
     );

lib/NGCP/Panel/Utils/Navigation.pm

@@ -81,9 +81,14 @@ sub check_form_buttons {
     delete $form->values->{back} if $posted;
 }
 
+sub select_back_target {
+    my ($c, $alternative_target) = @_;
+    return $c->stash->{close_target} || $alternative_target || $c->req->uri;
+}
+
 sub back_or {
     my ($c, $alternative_target, $nodetach) = @_;
-    my $target = $c->stash->{close_target} || $alternative_target || $c->req->uri;
+    my $target = select_back_target($c, $alternative_target);
     $c->response->redirect($target);
     $c->detach unless($nodetach);
 }