Modules page cleanup

[jenlampton]

1. Add a search box at the top like Drupal 8 has done
2. Hide the requires / required by information
3. Add a drop-button in the operations column (default: configure)

[quicksketch]

Merged in backdrop/backdrop#424. This looks amazing! Thanks!

[klonos]

I'm an old-timer. I like to see dependencies. So, how does this work now? Do dependencies only appear when not met?

[quicksketch]

@klonos there's a "more" link after the description that you click to show all dependencies, they're just hidden until you click on it.

[klonos]

Ahh! Thanx.

I thought that the 'more' link was to take you to a backdrop/drupal website page with more info about the module. Now I got it.

[docwilmot]

I suggest the search box also find dependencies. That way when you just installed a new module and search for it, you don't have to hunt down the dependencies separately. And optionally display the contents of the "more" link so its obvious.
I know bd will ask if you want to enable dependencies if you dont enable them first, but sometimes I prefer to enable things one by one, in case hell breaks loose.

[docwilmot]

Optionally, newly installed modules could be displayed in a separate container at the top of the modules page, with their dependencies, to make them easier to find.

[klonos]

...for historic reasons, @docwilmot's suggestion was captured in #532