Add additional Azure DevOps (TFBuild) properties

[flcdrg]

There's a few missing properties on the TFBuild classes for Azure DevOps Pipeline build variables, documented in https://docs.microsoft.com/en-us/azure/devops/pipelines/build/variables?view=azure-devops&tabs=yaml

Working on a PR to add these in

[flcdrg]

I just noticed that @gitfool has done a couple of these recently (eg. Reason)

[gitfool]

I was more focused on laying the foundation for identifying a pull request, across multiple providers, rather than capturing every last detail.

You can double check against this PR build on Azure Pipelines to confirm all the environment variables and what the actual values look like.

[flcdrg]

Probably good timing then that I come after your commit and can add on to your work, given you've looked at the other providers as well.

👍

[devlead]

fixed by #2492