Swimlanes: Add group_by URL param
Similar to how we sort on list pages (https://gitlab.com/gitlab-com/www-gitlab-com/-/issues?sort=due_date), we should add a query param that allows the user to go directly to a group by view.
Similar to how we sort on list pages (https://gitlab.com/gitlab-com/www-gitlab-com/-/issues?sort=due_date), we should add a query param that allows the user to go directly to a group by view.