Administration: Add new get_views_links method to WP_List_Table.
Many WP_List_Table child classes in core use mostly the same code to create their "view" links markup. To DRY-up the code, a new WP_List_Table->get_view_links method is being introduced to consolidate the HTML link generation when provided an array of links.
This change also implements this new method in the relevant WP_List_Table_xxx child classes get_views methods. Finally, unit tests are being added to validate view links markup and test for some "unhappy paths".
Props afercia, costdev, garrett-eclipse, Dharm1025, juhise, peterwilsoncc.
Fixes #42066.