feat($resource): add support for timeout in cancellable actions

Old behavior: actions can be either cancellable or have a numeric timeout.
When having both defined, cancellable was ignored.
With this commit: it's possible for actions to have both cancellable:true
and numeric timeout defined.

Example usage:

```js
var Post = $resource('/posts/:id', {id: '@id'}, {
  get: {
    method: 'GET',
    cancellable: true,
    timeout: 10000
  }
});

var currentPost = Post.get({id: 1});
...
// the next request can cancel the previous one
currentPost.$cancelRequest();
currentPost = Post.get({id: 2});

// any of those requests will also timeout, if the response
// doesn't come within 10 seconds
```

Closes #13824