Selecting a column in a table header by keyboard drops the focus

Problem/Motivation

If you change the column a table is sorted by on for example admin/content from updated to content type by pressing the return button, then the focus order is reset. The next tab brings up the "Skip to main content" link, you are back at the top of the DOM (SC3.2.1 & SC2.4.3 - check table_header_focus_drop.mp4).

Discussed and iterated on the issue with @mgifford, @the_g_bomb, @katannshaw, and @drupa11y

Steps to reproduce

• Tab through the table header on for example admin/content and change the column the table is sorted by by keyboard.

Proposed resolution

• Keep the focus in the table header cell the return button was pressed in.

Remaining tasks

User interface changes

API changes

Data model changes