OO-348: add CSS classes for the catalog entry chooser

src/main/java/org/olat/catalog/ui/_content/catalogentryajaxadd.html

+<div class="o_sel_catalog_chooser_tree">
 <h4>$r.translate("catalog.tree.add.title", ["$entryname"])</h4>
 <p>
 	$r.translate("catalog.tree.add.intro", ["<br/><strong>$entryname</strong><br/>"])
@@ -6,4 +7,5 @@ $r.render("treeCtr")
 <div class="b_button_group">
 	$r.render("select")
 	$r.render("cancel")
+</div>
 </div>
\ No newline at end of file

src/main/java/org/olat/course/editor/PublishStepCatalog.java

@@ -162,6 +162,7 @@ class PublishStepCatalog extends BasicStep {
 			flc.contextPut("choice", value);
 			boolean activate = "yes".equals(value);
 			addToCatalog = uifactory.addFormLink("publish.catalog.add", flc, Link.BUTTON_SMALL);
+			addToCatalog.setElementCssClass("o_sel_publish_add_to_catalog");
 			addToCatalog.setVisible(activate);
 			if(activate) {
 				List<CatalogEntry> catalogEntries = catalogManager.getCatalogCategoriesFor(repositoryEntry);