Create an about:adblock page

[bbondy]

The first version would be very simple, you can follow along how about:payments is done for a simple example, or about:newtab is done in WebUI for a more complicated example.

It should be the same redux format as the newtab page.

The first version would just say the blocked count.
It would also indicate if a regional list is in use and if so which one it is.

Later we'll add more features to this page like custom filters.

[bbondy]

wrong repo!