create terraform backends from the UI

[glennmusa]

Description

This update changes how the front-end creates the required resources to deploy the MLZ Configuration Resources (the Service Principal and KeyVault(s)) and terraform backend resources (storage accounts and containers. KeyVaults, contributor roles).

To give this a shot, login to a commercial cloud using the AZ CLI and try:

src/scripts/setup_ezdeploy.sh -s {sub_id}

The high points are:

1. updates setup_ezdeploy.sh to use many more defaults and deploy an operational front-end with just: ./setup_ezdeploy.sh -s {sub_id}

2. refactors setup_ezdeploy.sh to call multiple files

   • scripts/setup_ezdeploy_local.sh if the docker strategy local is specified
   • scripts/container-registry/create_acr.sh to create new Azure Container Registry instances from an mlz_tf_cfg.var
   • scripts/container-registry/deploy_instance.sh to deploy a container into the new ACR
   • scripts/container-registry/add_auth_scopes.sh to add User.Read permissions for the container in the ACR

3. introduces scripts/config/generate_config_file.sh as a way to consistently create new mlz_tf_cfg.var files to drive deployments from the shell or UI and allows for setting defaults (like, say, a user doesn't specify a T0 subscription id, it will default to the configuration subscription ID)

4. updates the front end to use defaults for user-supplied values for Hub through Tier 2

5. introduces a new means of gathering user input instead of get_opts:

   • this allows a user to specify the arguments in any order and with longer, more-descriptive names if needed

6. adds checkfordocker.sh to check for tooling requirements

Issue reference

The issue this PR will close: #140

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

[Breanna-Stryker]

Awesome refactor, this looks great and is far more maintainable.