feat: adding child platform management groups

[sdeguchi]

Overview/Summary

Adding platform/landingzone child management groups to architecture definition file.

This PR fixes/adds/changes/removes

1. Adds platform/landingzone child management groups to architecture definition file.
2. Changes architecture definition creation to use json objects
3. Adds templating for management groups IDs
4. Removes old architecture definition template file
5. Adds new architecture definition template file

Breaking Changes

1. Old architecture definition template file is no longer supported.

Testing Evidence

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.

[jaredfholgate]

LGTM. Nice improvement. :)