feature(views) Eases extending the input/view view

In order to extend forms *outside* the form element, devs must extend the 
input/form view, however it's a bit cumbersome to determine the current
action because you have to extract it from the "action", which is a URL. This
gives the extending view the raw action name.

Fixes #6129
Merge pull request #6348 from mrclay/6129

Eases extending the input/view view