Update section on debugging QA test pipeline failures

Why is this change being made?

To add details on handling non-test-related pipeline failures, and provide examples of non-test related failures.

• Add more examples of system failures and instructions on creating issues for system failures
• Revise links to pipeline schedules to not direct to the edit view
• Add note about staging Docker image
• Fix link to nightly pipelines page to be consistent with other links
• Replace acronym TAE with SET
• Re-wording

I tried to replace usage of 'test failures' with 'test pipeline failures', since failures are not always test-related

Does this MR meet the acceptance criteria?

Conformity

• Added description to this MR explaining the reasons for the proposed change, per say-why-not-just-what