Banner policy UI

We use several banners in GitLab that pop up depending on whether you're on a new browser or not, etc.

It's annoying to see the same banner twice. I'd much prefer it to never show a banner again after it's been seen once. That would mean we would have to record the status of showing one in the database.

1. Never show a banner again after dismissing in any project
2. Empty states should be used over banners whenever possible, because they are actionable and only applicable before usage.
3. Never use banners to replace good UI or great empty states