feat(GlButton): Add language around groups of danger buttons

Updates the language around usage of the danger button variant in a list or group of items that contain a danger button. This creates an edge case where you should consider using the default variant in these cases, but isolated danger buttons should be treated as danger buttons, regardless of whether they have a confirmation/interstitial or not due to the nature of their importance next to other more generic actions and for easier scanability when the intent is to delete something from a specific page (like when deleting your account).