DRAFT: Add changes to support deployment to Azure Container Apps

[abhahn]

Motivation and Context

Azure Container Apps can enable easy scaling of the webapp in production, and has been specifically asked for by customers previously. This PR makes a few small changes to support easy deployment to ACA from source.

Description

• Updated the app to check for the presence of X-Ms-Client-Principal as a proxy for identity provider configuration when using Azure Container Apps, which doesn't support the token store in the same way as Azure App Service does.
• Renamed the dockerfile to allow easy deployment from source (no option to pass in a specific named file when creating the app)

Contribution Checklist

• [ ] I have built and tested the code locally and in a deployed app
• [ ] For frontend changes, I have pulled the latest code from main, built the frontend, and committed all static files.
• [ ] This is a change for all users of this app. No code or asset is specific to my use case or my organization.
• [ ] I didn't break any existing functionality :smile: