enable the UI in other clouds

[glennmusa]

Description

This change makes it so that the UI will launch and successfully 'Execute Terraform' in a cloud other than AzureCloud by sourcing the Key Vault DNS suffix, the ARM Metadata Service Endpoint, the AAD login endpoint, and the Cloud Name from config.

To test this in say AzureUsGovernment try:

az cloud set -n AzureUsGovernment
az login
src/scripts/setup_ezdeploy.sh -s {your_subscription_id} -l usgovvirginia -e usgovernment

Issue reference

The issue this PR will close: #144, #151

Checklist

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

• Code compiles or validates correctly
• BASH scripts have been validated using shellcheck
• All tests pass (manual and automated)
• The documentation is updated to cover any new or changed features
• Markdown files have been linted using the recommended linter. (See .vscode/extensions.json.)
• Relevant issues are linked to this PR

[brooke-hamilton]

I deployed this to US Gov and Azure commercial.