Revisit page header "back button" component

[ajb]

It doesn't work in Screendoor: https://github.com/dobtco/screendoor-v2/pull/2243

Which leads me to believe that we might need to rework the component a bit.

[jrubenoff]

From that aforementioned issue:

The major [problem] is that if we remove the project name from the header, then a user has no way to tell which project they're currently inside of.

We can solve this with some lightweight breadcrumbs, like on forms.fm.

You also mentioned weird redundancies, like:

These seem pretty easily solvable to me:

@ajb, we definitely need to think through Screendoor's info hierarchy before implementing this, but: are there any other problems you can think of with the component itself?

[ajb]

:+1: