Add an outline to table cell that is in focus. ...

Note we use the css :focus-within psuedo class that is not supported in either
IE or Edge
https://developer.mozilla.org/en-US/docs/Web/CSS/:focus-within

Fix #2170

Fix to improve screen visibility when using zoomText or Windows Magnifier. ...

Changed default font-family for body ans Bootstrap tooltips and popovers t
  font-family: Verdana, Trebuchet, "Helvetica Neue", Helvetica, Arial, sans-serif;

Fix for #2172.

Fix for providing a highly visible highlighting mechanism for links or controls when they receive keyboard focus. ...

(WCAG 2.0, Additional Techniques (Advisory) for Sucess Criterion 2.4.3, https://www.w3.org/TR/UNDERSTANDING-WCAG20/navigation-mechanisms-focus-order.html)

Changes:

- Added an outline to links, buttons, select menus and other bootstrap form controls.
- The outline colour was set to #107896 (Darkest Alice Blue) which is the default colour for links.
- The default outline with set to 2px, except for buttons where it is set to 3px
to improve visiblity.

Fix for #2170.

Update asset structure with webpacker gem