consolidate platform-specific behaviors ahead of splitting out actions gem

[marcparadise]

Description

This change pays back some long-overdue tech debt by consolidating platform-specific functionality behind a common TargetHost interface. These behaviors were previously spread across actions, the base action class, and targethost.

Other changes:

• renaming vars/methods for clarity
• prune unused functions
• Some BOOTSTRAP TODOs to flag areas of concern for the upcoming knife bootstrap work

Signed-off-by: Marc A. Paradise marc.paradise@gmail.com

Issues Resolved

Check List

• [x] New functionality includes tests
• [x] All tests pass
• [x] PR title is a worthy inclusion in the CHANGELOG
• [x] You have locally validated the change