Add fixes to Azure

[sajohnstone]

I have

1. Added a make file and updated the readme
2. Fixed missing application_id
3. Made KeyVault, Firewall, UC Creation and Test VM as optional
4. Small refactor to put locals into locals.tf and datasoruces in datasources.tf
   To add a bit of context to the above, we've found that making things optional makes it much easier for testing, but also for deployments into environments that already have UC.

[JDBraun]

thanks for the contribution @sajohnstone!

cc: @nathanknox @connorbrown-db @eliswanson-db

[nathanknox]

Thanks @sajohnstone this looks great! I happen to be working on a refactor myself, addressing some of these exact things. I'm working on a review of your changes and am looking forward to collaborating. Would you be willing to review my changes as well as collaborate on the PR?

[connorbrown-db]

A few questions/finds on my end. Agree with @nathanknox - I know he has a few changes in flight and it might be good to review his PR also when it is ready.

[sajohnstone]

@nathanknox yes, very happy to review your PR and work in collaboration.