Add system level testing which can be run locally and in C-ACI

[DomAyre]

To be down-streamed to forks.

• Adds a docker-compose service for the CCF sandbox which can be run locally and will be runnable in ACI. This separation will make subbing other CCF deployments (local/mccf/azure-cleanroom/etc.) trivial
• Adds makefile targets to bring the service up and down and then KMS code/constitution etc. can be applied.
• Tests use these to spin up KMS's then tests endpoints

Todo:

• Add more scenarios for all endpoints
• Implement setting up KMS constitution including test JWT issuer
• Implement running in ACI

UPDATE: deferring for future PR

• Handle flakiness in deploying KMS to C-ACI CCF network
• Add a cleanup workflow for C-ACI deployments
• Add tests for good and bad attestations
• Add tests for live attestations
• Add tests for unwrapKey

Issues found so far (currently more nitpicks and probably aren't blockers):

• Heartbeat endpoint has typo /hearthbeat #168
• Key endpoints returns 400 when there aren't any keys #167
• /keyReleasePolicy returns 500 when no key release policy is set #175
• /keyReleasePolicy returns potentially unexpected values #176
• Make Endpoints casing consistent #177
• /key endpoint ignores the body field wrappingKey #179

[DomAyre]

Since running in ACI for CI is a bit flaky and we don't want to block fixing the issues, I suggest we merge this as is @beejones if you're happy with this?