[DBEX] log and monitor form 4142 failure email events

[freeheeling]

Summary

• This work is behind a feature toggle (flipper): YES/NO
• (Summarize the changes that have been made to the platform)
  • Logs unresolved silent failures, when a form 4142 failure email job fails to enqueue
  • Removes unnecessary memoization and methods in Form0781DocumentUploadFailureEmail based on feedback received in [DBEX] log and monitor evidence upload failure email events #19097
• (If bug, how to reproduce) N/A
• (What is the solution, why is this the solution?)
  • Logs messages identified as silent failures
  • Increments metrics to capture an issue
  • Supports logging and metrics requirements set by VA stakeholders
• (Which team do you work for, does your team own the maintenance of this component?)
  • Disability Benefits Experience Team 2 (dBeX Carbs 🥖), which owns maintenance of all files in this PR
• (If introducing a flipper, what is the success criteria being targeted?) N/A

Related issue(s)

• [DD] Logging resolved failures for Ancillary forms va.gov-team#95092

Testing done

• New code is covered by unit tests

What areas of the site does it impact?

(Describe what parts of the site are impacted andifcode touched other areas)

• Impacts logging and metrics data recorded in Datadog

Acceptance criteria

• I fixed|updated|added unit tests and integration tests for each feature (if applicable).
• No error nor warning in the console.
• Events are being sent to the appropriate logging solution
• Documentation has been updated (link to documentation)
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• Feature/bug has a monitor built into Datadog (if applicable)
• If app impacted requires authentication, did you login to a local build and verify all authenticated routes work as expected
• I added a screenshot of the developed feature