Add card hover and dynamic board widths

What does this MR do and why?

Improves handling of board content width when work item drawer is open. Previously, some columns would be unreachable when the drawer was open, now they can all be scrolled across to.

Adds a hover effect to board cards to match designs.

Note: clicking the board card title does not currently open the drawer, this will be addressed in a separate MR.

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After
Screen_Recording_2024-09-20_at_11.52.48	Screen_Recording_2024-09-20_at_11.49.28

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Enable the work item drawer with the issues_list_drawer feature flag.
2. Visit a board, and click a card on the board.
3. Check you can scroll horizontally and view all columns on the board still. (On a very small screen the drawer will be full-screen so scrolling isn't possible).

Relates to #465852 (closed)