LP1615707 ARIA landmarks for staff interface

LP1615707 ARIA landmarks for staff interface

Adds the following ARIA landmarks and roles to the Angular staff
interface:

* <main> and role="main" for the content container
* <nav> and role="navigation" for the navbar
* role="form" for the catalog search form (which lacks a <form> tag)
* role="search" for the search tab panel inside the form
* type="search" and role="searchbox" for the search term input field
* a custom region for the bib record summary box
* <aside> and role="complementary" for the facet sidebar

To construct the ARIA label for the bib record summary, I've added an ID
to the header row of the bib summary component so the screen reader can
use the localized text.

Since the staff interface doesn't really have a header section other
than the navigation, and there is no footer, I've left out these
landmarks.

Signed-off-by: Stephanie Leary <stephanie.leary@equinoxOLI.org>