Add ability to skip provider registrations for the terraform azure provider.

[lagosr-google]

Description

Only affects AZURE deployments.

Will configure the azurerm TF provider to skip_provider_registrations when the variable AZURE_SKIP_PROVIDER_REGISTRATION is set to "true".

The variable is defaulted to "false" and set as optional.

Tested by deploying onto azure.

Checklist

General

• Added the correct label
• Assigned to a specific person or civiform/deployment-system
• Created tests which fail without the change (if possible)
• Performed manual testing (at a minimum run bin/setup without your changes and then bin/deploy with your changes to ensure your changes don't break existing deployments)
• Extended the README / documentation, if necessary

Instructions for manual testing

Ran the azure deployment script. -- Documentation for AZURE deployments is in progress.