Alter code monitors pages to correct create button in header

Created by: rrhyne

The code monitor create code monitor button should:

1. Be labeled "Create code monitor"
2. Should appear on both the create code monitor page and getting started page at all times
3. In the case of an empty code monitor page, the empty state button should be removed.

Figma of problem areas and corrections: https://www.figma.com/file/ZzWVJSMGKYDMLbfIAqWCvX/Consistency-of-primary-actions?node-id=14%3A951