Make nuxeo-data-grid cards focused when using a keyboard

related to WCAG 2.1 level A criteria 2.1.1: Keyboard
https://www.w3.org/TR/WCAG21/#keyboard

Make nuxeo-data-grid cards usable with keyboard only.

AC

• Using the keyboard, I can access any nuxeo-data-grid card
• I can navigate within the grid using the arrow keys as described in https://www.w3.org/WAI/ARIA/apg/patterns/grid/ (e.g., left and right keys, up and down, etc. - attached in this ticket as well)

• when a particular thumbnail is active, it receives focus so that I can understand which element I am interacting with
  • Actions in the bottom of the card become visible
  • Selection action becomes visible

Location

• "Search results" section

Except for the first item in the search results section, all the other links do not receive the keyboard focus and are not accessible using the keyboard alone.

Recommendation to fix
RULE :
Functionality MUST be available using the keyboard, unless the functionality cannot be accomplished in any known way using a keyboard.

HOW TO FIX
Fix this issue by ensuring the component can be used by the keyboard OR by providing a conformant alternate functionality method for the action

REFERENCE
Aria grid pattern
Deque University:https://dequeuniversity.com/class/input-methods2/keyboard-input/functionality

BACKGROUND
Some people cannot use a mouse due to vision or motor disabilities. Content that can be operated with a mouse must also be made operable with a keyboard. When content is operable through a keyboard, it becomes operable by a variety of assistive technologies such as speech input software, sip-and-puff software, on-screen keyboards, scanning software, and alternate keyboards.