[ADF-1412] Viewer enhancements (#2873)

* collection navigation support for Viewer

* code cleanup

* full screen mode support

* keyboard shortcuts

* zooming scale label

* layout fixes

* test fixes

* image toolbar with basic tranformations

* test fixes

* test fixes

lib/core/mock/event.mock.ts

@@ -24,6 +24,13 @@ export class EventMock {
         document.dispatchEvent(event);
     }
 
+    static keyUp(key: any) {
+        let event: any = document.createEvent('Event');
+        event.keyCode = key;
+        event.initEvent('keyup');
+        document.dispatchEvent(event);
+    }
+
     static resizeMobileView() {
         // todo: no longer compiles with TS 2.0.2 as innerWidth/innerHeight are readonly fields
         /*