Remove page header from organizations empty state

The following discussion from !132418 (merged) should be addressed:

• @gdoyle started a discussion: (+5 comments)

  I'm creating a follow-up to remove the header in the empty state. We don't need the page title or the New organization button since we can rely purely on the empty state content and action 🙇.

Proposal

Remove page header including the title and the button.