feat: improve deployment stack names

[jaredfholgate]

Overview/Summary

• Improve deployment stack names
• Support single region for Bicep
• Improve subscription id validation and remove legacy variables

This PR fixes/adds/changes/removes

1. Bug: Input not supplied, and no default for secondary_location Azure-Landing-Zones#2311

Breaking Changes

None

Testing Evidence

Please provide any testing evidence to show that your Pull Request works/fixes as described and planned (include screenshots, if appropriate).

As part of this Pull Request I have

• Checked for duplicate Pull Requests
• Associated it with relevant issues, for tracking and closure.
• Ensured my code/branch is up-to-date with the latest changes in the main branch
• Performed testing and provided evidence.
• Updated relevant and associated documentation.