azure blob storage upload support

[AnthonyApptio]

What does this PR do?

Adds support for uploading to a custom Azure blob storage. Also adds support for azure managed identity blob storage uploads.

Where should the reviewer start?

How should this be manually tested?

Created an image based on this build and applied the image to a metrics-agent yaml.
Set all custom azure env vars with the correct values.
Deployed that metrics-agent to a test cluster.
Confirm uploads to the Azure blob container name provided.
Tested the default upload with this new image to ensure backwards compatibility.

Any background context you want to provide?

What picture best describes this PR (optional but encouraged)?

What are the relevant Github Issues?

Developer Done List

• Tests Added/Updated
• Updated README.md
• Verified backward compatible
• Verified database migrations will not be catastrophic
• Considered Security, Availability and Confidentiality

For the Reviewer:

By approving this PR, the reviewer acknowledges that they have checked all items in this done list.

Reviewer/Approval Done List

• Tests Pass Locally
• CI Build Passes
• Verified README.md is updated
• Verified changes are backward compatible
• Reviewed impact to Security, Availability and Confidentiality (if issue found, add comments and request changes)