[Feature] Rationale is needed for new tests in the Security category

[lixuna]

Is your feature request related to a problem? Please describe.

• Rationale is needed for new tests in the Security category

Describe the solution you'd like Add rationale details to https://github.com/cncf/cnf-testsuite/blob/main/RATIONALE.md and link to/from USAGE.md for:

• [ ] https://github.com/cncf/cnf-testsuite/blob/main/USAGE.md#heavy_check_mark-to-check-if-a-cnf-is-using-container-socket-mounts
• [ ] https://github.com/cncf/cnf-testsuite/blob/main/USAGE.md#heavy_check_mark-to-check-if-any-pods-in-the-cnf-use-sysctls-with-restricted-values
• [ ] https://github.com/cncf/cnf-testsuite/blob/main/USAGE.md#heavy_check_mark-to-check-if-a-cnf-is-running-services-with-external-ips
• [ ] https://github.com/cncf/cnf-testsuite/blob/main/USAGE.md#heavy_check_mark-to-check-if-there-are-service-accounts-that-are-automatically-mapped
• [ ] https://github.com/cncf/cnf-testsuite/blob/main/USAGE.md#heavy_check_mark-to-check-if-cnf-resources-use-custom-selinux-options-that-allow-privilege-escalation

[agentpoyo]

Verifying this now as these should have been addressed in other documentation issues.

[agentpoyo]

Verified that all these are now in RATIONALE with descriptions.