Focus Visibility & Order via Keyboard Input

_*This is an important feature for users that require screen readers or use keyboard-only input to access content._

**General UI**: There is no visible focus style for _all interactive elements_ that are navigated to via keyboard input (both menu and table elements lack a focus style, for example the blue highlights surrounding buttons).

**[Example] Shared folders page:** The keyboard focus order for this page does not match the visual layout.

https://images.zenhubusercontent.com/285884697/7231b8fa-fe36-4365-a3dd-3db64d522ad8/focus_order_via_keyboard_input.mov

Start with the Shared folders page and review the attached focus-order recording alongside the rendered UI. Inspect the keyboard navigation for menus, tables, and other interactive elements; done means every keyboard-focused element has a visible focus style and the traversal order matches the visual layout.

Written by the indexing model from the issue text.