refactor(): restructure components to loosen coupling, move overlay-portal, click-block, menu-controller and other app-level functionality to app directory. The motivation for this change is logical grouping, decoupling components from each other, and improving the ability to drop more unused components from bundle

src/gestures/slide-gesture.ts

@@ -1,4 +1,4 @@
-import { PanGesture } from './drag-gesture';
+import { PanGesture } from './pan-gesture';
 import { clamp, assert } from '../util/util';
 import { Platform } from '../platform/platform';
 import { pointerCoord } from '../util/dom';