ui: use executable template filter for users (#3214)

Problem: When reinstalling a VM, the UI only shows featured templates and not all possible list of allowed templates.
Root Cause: The list of templates for reinstall used featured as filter in ‘listTemplates’ API which did not include all available options.
Solution: The issue is fixed by using the executable template filter of the ‘listTemplates’ API to list all
possible templates that a user is allowed to use to deploy a VM.

ui/scripts/instances.js

@@ -1137,7 +1137,7 @@
                                     label: 'label.select.a.template',
                                     select: function(args) {
                                         var data = {
-                                            templatefilter: 'featured'
+                                            templatefilter: 'executable'
                                         };
                                         $.ajax({
                                             url: createURL('listTemplates'),