Fix wonky tables on dashboard and activity page
Fix wonky tables on dashboard and activity page

Tables with a `layout` of `fixed` determine column widths from the
width of the column headings.

We weren’t setting the width of the first column heading, so our tables
were getting out of alignment.

alphagov/notifications-admin,gov-cjwaszczuk/notifications-admin,alphagov/notifications-admin,gov-cjwaszczuk/notifications-admin,alphagov/notifications-admin,alphagov/notifications-admin,gov-cjwaszczuk/notifications-admin,gov-cjwaszczuk/notifications-admin