R1:cb481f36c54b

Carve out a separate "Services" section of Config

Summary: Depends on D20930. Ref T13362. Put all the "Services" parts of Config in their own section.

Test Plan: Clicked through each section. This is just an organization / UI change with no significant behavioral impact.

Maniphest Tasks: T13362

Differential Revision: https://secure.phabricator.com/D20931