🎨 Adjusted post settings menu design so it can stay open whilst editing

refs TryGhost/Product#840

We wanted to switch to a settings menu that stays open to the right of the editor rather than a popover that blocks all other interaction with the post to solve two use-cases:

1.  when editing it's fairly common to select some text from the post contents when setting excerpt and meta data text, with the previous design not letting you scroll or select whilst the menu got in the way of that
2. having the menu open with meta data visible before publishing can help you see everything is set as you want and help you feel confident when publishing/sending content

---

- removed `psmRedesign` labs flag
- swapped labs component/css for main component and deleted labs component
- cleaned up now-unused `ui.showSettingsMenu` property and related actions/classes

app/components/gh-app.hbs

@@ -1,3 +1,3 @@
-<div class="gh-app" {{did-insert this.setBodyClass}} {{did-update this.setBodyClass @showSettingsMenu}} ...attributes>
+<div class="gh-app" ...attributes>
     {{yield}}
 </div>

app/components/gh-editor.hbs

@@ -1,5 +1,4 @@
 {{yield (hash
-    headerClass=this.headerClass
     headerHeight=this.headerHeight
     isDraggedOver=this.isDraggedOver
     isFullScreen=this.isFullScreen

app/components/gh-editor.js

@@ -19,7 +19,6 @@ export default Component.extend({
 
     // Internal attributes
     droppedFiles: null,
-    headerClass: '',
     headerHeight: 0,
     imageExtensions: IMAGE_EXTENSIONS,
     imageMimeTypes: IMAGE_MIME_TYPES,
@@ -33,29 +32,10 @@ export default Component.extend({
     _onResizeHandler: null,
     _viewActionsWidth: 190,
 
-    init() {
-        this._super(...arguments);
-        this._onResizeHandler = (evt) => {
-            debounce(this, this._setHeaderClass, evt, 100);
-        };
-    },
-
-    didInsertElement() {
-        this._super(...arguments);
-        window.addEventListener('resize', this._onResizeHandler);
-        this._setHeaderClass();
-    },
-
-    willDestroyElement() {
-        this._super(...arguments);
-        window.removeEventListener('resize', this._onResizeHandler);
-    },
-
     actions: {
         toggleFullScreen(isFullScreen) {
             this.set('isFullScreen', isFullScreen);
             this.ui.set('isFullScreen', isFullScreen);
-            run.scheduleOnce('afterRender', this, this._setHeaderClass);
         },
 
         togglePreview(isPreview) {
@@ -64,7 +44,6 @@ export default Component.extend({
 
         toggleSplitScreen(isSplitScreen) {
             this.set('isSplitScreen', isSplitScreen);
-            run.scheduleOnce('afterRender', this, this._setHeaderClass);
         },
 
         uploadImages(fileList, resetInput) {
@@ -85,40 +64,6 @@ export default Component.extend({
         }
     },
 
-    _setHeaderClass() {
-        if (this.feature.psmRedesign) {
-            return;
-        }
-
-        let editorTitle = this.element.querySelector('.gh-editor-title, .kg-title-input');
-        let smallHeaderClass = 'gh-editor-header-small';
-        let newHeaderClass = '';
-
-        this._editorTitleElement = editorTitle;
-
-        if (this.isSplitScreen) {
-            this.set('headerClass', smallHeaderClass);
-            return;
-        }
-
-        if (editorTitle) {
-            let boundingRect = editorTitle.getBoundingClientRect();
-            let maxRight = window.innerWidth - this._viewActionsWidth;
-
-            if (boundingRect.right >= maxRight) {
-                newHeaderClass = smallHeaderClass;
-            }
-        }
-
-        if (newHeaderClass !== this.headerClass) {
-            // grab height of header so that we can pass it as an offset to other
-            // editor components
-            run.scheduleOnce('afterRender', this, this._setHeaderHeight);
-        }
-
-        this.set('headerClass', newHeaderClass);
-    },
-
     _setHeaderHeight() {
         if (this.headerClass && this._editorTitleElement) {
             let height = this._editorTitleElement.offsetHeight;