href route template attribute

Currently the pagination controls have anchors with an empty href in them.
You can change this by overriding the template, but it would be nice to have an attribute where you can pass in a route.
Example:

``` html

```

In this case people could just use this attribute instead of the callback if they only change the location in the callback.
But for me the main benefit is from a SEO standpoint, so browsers can follow the links.

Start by locating the dir-pagination-controls directive and its anchor template, then inspect how the callback and href are currently handled. Done means an href-template such as /blog/page/:pageNumber can generate browser-followable pagination links without requiring the callback.

Written by the indexing model from the issue text.