Fix: Harden sig_term_handled test

[svteb]

Description

• Prior implementation of the test did not correctly handle strace failures, resulting in the task being fragile and failing on ephemeral/untracable processes.
• Above issues were resolved by adding correct error handling on expected errors.
• The code structure was also flattened for better readability.

After reading the prior implementation I decided to make some changes that may change the outcome of the task, the task would previously fail if the container to be checked was not ready/could not be found (really odd edge cases). These cases were considered skipped, but would still cause failure. I changed them to be true skips (not affecting the end result).

I would like to test this a little further, maybe add an additional spec test, so for now its in draft state.

Issues:

Refs: #2223

How has this been tested:

• Covered by existing integration testing
• Added integration testing to cover
• Verified all A/C passes
  • develop
  • master
  • tag/other branch
• Test environment
  • Shared Packet K8s cluster
  • New Packet K8s cluster
  • Kind cluster
• Have not tested

Types of changes:

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Checklist:

Documentation

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• No updates required.

Code Review

• Does the test handle fatal exceptions, ie. rescue block

Issue

• Tasks in issue are checked off