refactor: lots of fixes + cleanup

[afiune]

Summary

This change is fixing the following things:

• Renames inputs from this module
  • prefix cloudformation inputs with cf_
  • remove - from subaccount (like the provider)
  • secrets start with lacework_access_
• Remove external ID generation
• make stack_name a variable
• removes unnecessary provider dependencies

How did you test this change?

I have not. Waiting on @jefferyfry changes at https://github.com/lacework-alliances/aws-org-cf-lacework

Issue

N/A

[ipcrm]

There are more changes behind this to fix, merging this as interim step.