Read/write bundles to/from Azure Blob Storage

[angelathe]

PULL REQUEST

Summary

What changes are being proposed?

• Add functionality to read/write FHIR bundles to/from Azure blob storage
• Add env vars
• Add mock API tests

Note: Currently, we don't have access to Azure, so I used placeholder env vars and had to move a couple lines around so things wouldn't error out.

Related Issue

Fixes #2398

Checklist

Don't know what testing can currently be done without DIBBs access to Azure?

Acceptance Criteria

• Adjust existing env vars or create a new one to allow configuring the app to save to Azure Blob storage rather than AWS
• Implement an Azure Blob Storage read and write (See linked docs below)
• Use conditional logic with the env var to save to blob storage when the app is configured for Azure
  Tests
• S3 read and write should work as normal if the app is configured for AWS

[austin-hall-skylight]

Tested with Azure storage emulator and everything is working

[gordonfarrell]

Looks really good, great work on this Angela! Just one tiny comment/question, gonna approve though so you don't have to hunt me down for a re-approval if it needs a change. Thanks!