Added scroll-into-view behaviour for inline image selector

refs https://github.com/TryGhost/Team/issues/1225

- added `scrollToCard` action to `koenig-editor` and passed it through to all card components curried to already include the card as an argument
  - action selects the card which places the cursor on it, then triggers our existing cursor scroll-into-view behaviour with an option to allow scrolling a card into view
- updated our cursor scroll-into-view behaviour so if the cursor is large (eg, when it covers a card's height) we make sure the top of the cursor is kept in view rather than the bottom
  - ensures that on small-height screens, opening the gif selector doesn't result in it's search bar being scrolled off screen

lib/koenig-editor/addon/components/koenig-card-image.js

@@ -180,6 +180,10 @@ export default Component.extend({
                 fileInput.click();
             }
         }
+
+        if (this.imageSelector) {
+            this.scrollToCard();
+        }
     },
 
     actions: {

lib/koenig-editor/addon/components/koenig-editor.hbs

@@ -100,6 +100,7 @@
             saveCard=(action card.env.save)
             cancelCard=(action card.env.cancel)
             removeCard=(action card.env.remove)
+            scrollToCard=(action "scrollToCard" card)
             isSelected=card.isSelected
             isEditing=card.isEditing
             selectCard=(action "selectCard" card)

lib/koenig-editor/addon/components/koenig-editor.js

@@ -696,6 +696,11 @@ export default Component.extend({
             this.deselectCard(card);
         },
 
+        scrollToCard(card) {
+            this.selectCard(card);
+            this._scrollCursorIntoView({jumpToCard: true});
+        },
+
         // range should be set to the full extent of the selection or the
         // appropriate <a> markup. If there's a selection when the link edit
         // component renders it will re-select when finished which should
@@ -1475,7 +1480,15 @@ export default Component.extend({
                 if (atBottom) {
                     this._scrollContainer.scrollTop = this._scrollContainer.scrollHeight;
                 } else {
-                    this._scrollContainer.scrollTop = scrollTop + offsetBottom + distanceFromViewportBottom + 20;
+                    let scrollAdjustment = offsetBottom + distanceFromViewportBottom + 20;
+                    let cursorFromTop = cursorTop - scrollAdjustment;
+
+                    // pull top of cursor back into view if the adjustment pushed it off top of screen
+                    if (cursorFromTop < 20) {
+                        scrollAdjustment = scrollAdjustment + cursorFromTop - 20;
+                    }
+
+                    this._scrollContainer.scrollTop = scrollTop + scrollAdjustment;
                 }
             }
         }