R1:48fc3126a124

Support autoscaling daemons in phd

Summary: Ref T7352. This supports passing autoscaling configuration to daemons, and adds `debug --autoscale`.

Test Plan: See D11711.

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T7352

Differential Revision: https://secure.phabricator.com/D11860