[RPD-315] Update provisioning/destroy message for modular stack

[JonoCX]

As we've introduced modular stacks, with differing components, the provisioning and destroy resources message that's presented to the user is incorrect - it's missing components.

This PR updates the generation of that message such that it's dynamically generated based on the stack that has been set by the user.

The get_stack() function has also been updated to streamline the dynamic generation. Previous, just the name was returned, now the whole stack component is returned.

Checklist

Please ensure you have done the following:

• I have read the CONTRIBUTING guide.
• I have updated the documentation if required.
• I have added tests which cover my changes.

Type of change

Tick all those that apply:

• Bug Fix (non-breaking change, fixing an issue)
• New feature (non-breaking change to add functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Other (add details above)

[Christopher-Norman]

LGTM nice work.