Add a "Template" column & Filter to Page post type

[acketon]

Responsive Version: Latest

Partial example @sr4136 added to CAS:

To make all of our lives slightly better can we add a "Template" column to the Pages post type admin screen and a filter (dropdown) to help people find pages with certain templates applied.

I'm sure we've all wasted time hunting through a site to find an example of a particular template applied to a page post.