enhancing dhtml view with some simple collapse/expand toggles

This commit marks my initial exploration into adding some basic collapse/expand toggles to the DHTML pickled view so as to better manage feature pages with lots of content.

- clicking on scenario background and scenario titles now toggles the visibility of related content;

- clicking on table headers now toggles the visibility of the table rows;

- show all / hide all tools show and hide scenario details across the page;

I am not attached to this set of interactions nor to the implementation, but wanted to illustrate the type of enhancements I'm interested in.

This is just the beginning of increasing the navigability of these DHTML feature descriptions.