Let touch-action be set on ShadowRoots and Document, watch ShadowDOM for mutations

In order to emulate the ability of setting touch-action on document and other DOM objects without attributes:
```css
html {
touch-action: none;
}
```

new API is added that allows for setting the touch-action imperatively.

The same API can be used to define touch-action on a ShadowRoot, and should be set to the same touch-action as the host element.

API:

```javascript
PointerEventsPolyfill.setTouchAction(element, touch-action);
```

Also added ability to watch ShadowDOM for touch-action property
```javascript
PointerEventsPolyfill.register(shadowRoot)
```