R1:d6514321b161

Add an Almanac service type for Drydock to lease against

Summary: Ref T9253. See D13843 for some discussion. This is very bare-bones for now since I believe that almost all interesting configuration (e.g., credentials) should live in Drydock, although I imagine it getting some configuration eventually.

Test Plan: Used {nav Almanac > Services > Create Service} to create a new service of this type.

Reviewers: hach-que, chad

Reviewed By: hach-que, chad

Maniphest Tasks: T9253

Differential Revision: https…