Add nightly and PR validation pipelines in Azure DevOps

[vidyambala]

Description

Adds Azure DevOps pipelines to:

• nightly deploy the Bicep solution into AzureCloud and AzureUsGovernment
• nightly deploy the Terraform solution into AzureCloud and AzureUsGovernment
• on PR into /main run a --what-if AZ CLI deployment to ensure the Bicep templates are deployable
• on PR into /main run a terraform plan to ensure the Terraform templates are deployable
• adds a resourcePrefix tag to the Terraform resources

Issue reference

The issue this PR will close #49 close #94 close #466

Checklist

Please make sure you've completed the relevant tasks for this PR out of the following list:

• All acceptance criteria in the backlog item are met
• The documentation is updated to cover any new or changed features
• Manual tests have passed
• Relevant issues are linked to this PR

[glennmusa]

Let's get the failed checks resolved.

Want to look at these two:

https://github.com/Azure/missionlz/runs/4117640642?check_suite_focus=true#step:4:462

and I'll take a look at why the Terraform validation check is failing -- the error message is cryptic:

https://github.com/Azure/missionlz/runs/4117640677?check_suite_focus=true

[glennmusa]

Thanks @vidyambala 🚀