Update dependency proxy copy and labels

Old issue description moved to this comment

Scope of this issue

Current	Change
	Change copy to: The Dependency Proxy is disabled. Learn how to enable it.
Dependency Proxy menu item isn't available until refresh after enabling	Add copy underneath enabled toggle (see design attached to this issue)

Related to this issue

• Improve the docs with more information about what permissions or roles are required to enable the Dependency Proxy
• Dependency proxy empty state