[IMP] web_editor: page options activated on click on the customize tab

With this commit, clicking on the "customize" tab automatically
activates the page options (if there are any). This commit also replaces
the name of the "style" tab by naming it "customize".

task-2710582

addons/web_editor/static/src/js/editor/snippets.editor.js

@@ -2948,7 +2948,18 @@ var SnippetsMenu = Widget.extend({
         if (!ev.currentTarget.classList.contains('active')) {
             this._activateSnippet(false);
             this._mutex.exec(() => {
-                this._activateEmptyOptionsTab();
+                let $pageOptionsTarget = $();
+                let i = 0;
+                const pageOptions = this.templateOptions.filter(template => template.data.pageOptions);
+                while (!$pageOptionsTarget.length && i < pageOptions.length) {
+                    $pageOptionsTarget = pageOptions[i].selector.all();
+                    i++;
+                }
+                if ($pageOptionsTarget.length) {
+                    this._activateSnippet($pageOptionsTarget);
+                } else {
+                    this._activateEmptyOptionsTab();
+                }
             });
         }
     },

addons/web_editor/views/snippets.xml

@@ -18,7 +18,7 @@
             <span>Blocks</span>
         </button>
         <button type="button" tabindex="2" class="o_we_customize_snippet_btn text-uppercase">
-            <span>Style</span>
+            <span>Customize</span>
         </button>
     </div>