fix(GlTable): update hover and selected primary background

mentioned in commit f9953bcb

mentioned in merge request gitlab-org/gitlab-services/design.gitlab.com!2444 (merged)

mentioned in merge request status-page!321 (merged)

mentioned in merge request gitlab!65484 (merged)

mentioned in merge request gitlab-org/gitlab-services/design.gitlab.com!2450 (merged)

mentioned in merge request status-page!322 (merged)

mentioned in merge request gitlab!65665 (closed)

mentioned in merge request gitlab!65711 (closed)

mentioned in merge request gitlab-docs!1959 (closed)

mentioned in merge request gitlab-docs!1968 (closed)