Escape docker output

Summary:
This adds a new DockerInstruction interface that can be implmented by
different docker instructions. DockerInstruction implements a compile
method that returns escaped output for use in a dockerfile.

Fixes T167999

Reviewers: dduvall, mmodell, Release-Engineering-Team

Reviewed By: dduvall, Release-Engineering-Team

Tags: Release-Engineering-Team

Maniphest Tasks: T167999

Differential Revision: https://phabricator.wikimedia.org/D705