Baseline work for launchpad / landingzone cmds

This is a huge PR, but you could argue when we're still building the baseline code of the applications, PRs don't really work, anyhow...

This PR includes:

Shared code for launchpad and landingzone commands in pkg/core
The many MANY params and vars for those commands to run, grouped into an Options data structure
Supporting changes in pkg/terraform to expand a directory to a set of --var-file options to pass to terraform
Number supporting functions in pkg/azure for handling
- Azure resource graph for finding resources
- Azure CLI interface for accessing the current subscription and signed in user
- Storage functions for finding storage accounts, getting access keys, and uploading blobs
New console functions to support tfexec logging

The result is a:

A functioning rover launchpad run command for the init, plan & deploy actions
The detection of existing state and switching to enabling a backend if found. Note. There is more to be done in this area
Uploading of local state when launchpad run is first run

aztfmod / rovergo