Implement the plan to handle failure cases

[reactive-firewall]

Basic Plan

1. Pre-Action

• if failure happens in the Pre-Action phase just report and abort.

2. Main Action

• As input is handled in the Pre-Action phase, failures in the Main Action phase are usually transient in nature and should cause a trivial reattempt and only abort on persistent errors.

3. Post-Action

• errors in the Post-Action phase are considered warnings and not failures. Ultimately these are out-of-scope and may be handled by reporting an exit-code as an exit would happen either way (crash is a non-fail result here).

Originally posted by @reactive-firewall in #18 (comment)

• implement the PLAN
  • implement report and abort handler
  • implement retry or fail handler