lp1828575 eg-grid options accessibility

lp1828575 eg-grid options accessibility
Modify the options menu of eg-grid so that you can open it and use it
via the keyboard. Improve accessibility in general.

Signed-off-by: Mike Risher <mrisher@catalyte.io>
 Changes to be committed:
	modified:   Open-ILS/src/eg2/src/app/share/grid/grid-column-config.component.html
	modified:   Open-ILS/src/eg2/src/app/share/grid/grid-column-width.component.html
	modified:   Open-ILS/src/eg2/src/app/share/grid/grid-header.component.html
	modified:   Open-ILS/src/eg2/src/app/share/grid/grid-toolbar.component.html

Signed-off-by: Jane Sandberg <sandbej@linnbenton.edu>