Add Azure support (for v3.4.0)

[takuro-sato]

This is a updated version of the previous PR because the latest commit at the time (v3.0.0) is now outdated.
It is created based on our current codebase which is based on v3.4.0, so we set the v3.4.0 release as the target.

The previous PR is left as it is because the branch is still used by our demo.

The new PR for data-plane-shared-libraries targets a branch with hash 1fbac46 (used by v3.4.0) in our fork because we can't create a PR against commits without branch name or tag in https://github.com/privacysandbox/data-plane-shared-libraries.

This PR targets a copy of the v3.4.0 release in our fork as well for consistency.

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Adding Azure support

This PR is adding support for enabling deployment of Bidding and Auction Services on Azure.

Azure Privacy Sandbox architecture: https://1drv.ms/w/s!AmI-86sms1pYqJ5Uqgo5Qv2Ynmrcmw?e=BDC8BH
(We'll make a PR for the document in https://github.com/privacysandbox/protected-auction-services-docs/tree/main in future)

Now B&A services can fetch private and public HPKE keys from an Azure KMS, specifically designed to support the B&A services, and handle test requests.

To try this changes locally, please visit here.

The PR for data-plane-shared-libraries repository: KenGordon/data-plane-shared-libraries#24
azure-privacy-sandbox-kms branch that works with this PR: https://github.com/microsoft/azure-privacy-sandbox-kms/tree/add-azure-support-v3.4.0

Changes

• Add Azure support
  • Add Azure configurations. e.g. --platform=azure (for Bazel), kAzure (C++ enum value).
  • Add Azure scripts and configuration files for production/packaging
  • Update some test cases to add test coverage for kAzure.

TODOs for future PRs

• Add scripts to Deploy B&A services to Azure