feat: expand support for versioned URLs in v2 XBlock runtime (#35676)

* fix: problem block could not be used with versioned handler URls

* refactor: simplify REST API handling of usage keys

* feat: add more version awareness and update tests

* fix: make the preview changes modal bigger as requested

* refactor: parse version at the urlconf layer too

cms/static/js/views/modals/preview_v2_library_changes.js

@@ -17,7 +17,7 @@ function($, _, gettext, BaseModal, ViewUtils, XBlockViewUtils) {
 
         options: $.extend({}, BaseModal.prototype.options, {
             modalName: 'preview-lib-changes',
-            modalSize: 'med',
+            modalSize: 'lg',
             view: 'studio_view',
             viewSpecificClasses: 'modal-lib-preview confirm',
             // Translators: "title" is the name of the current component being edited.

cms/static/sass/views/_container.scss

@@ -570,7 +570,7 @@
 
     & > iframe {
       width: 100%;
-      min-height: 350px;
+      min-height: 450px;
       background: url('#{$static-path}/images/spinner.gif') center center no-repeat;
     }
   }