102639 One debt letter endpoint

[digitaldrk]

Note: Delete the description statements, complete each step. None are optional, but can be justified as to why they cannot be completed as written. Provide known gaps to testing that may raise the risk of merging to production.

Summary

• This work is behind a feature toggle (flipper): YES/NO: No but it is not an endpoint that is or will be utilized for about a month or so.
• (Summarize the changes that have been made to the platform): We are beginning role out of our "One Debt Letter" feature. This is a PDF containing both "debts" and "copays". This adds the endpoint and the beginnings of a prawn service that will build and output a PDF.
• (If bug, how to reproduce): N/A
• (What is the solution, why is this the solution?): For the pdf, I tried using pdftk with a template. This didn't seem to handle the dynamic nature of the content.
• (Which team do you work for, does your team own the maintenance of this component?): Financial management. You can find me on #financial-management in OCTO Slack.
• (If introducing a flipper, what is the success criteria being targeted?): N/A

Related issue(s)

• Link to ticket created in va.gov-team repo OR screenshot of Jira ticket if your team uses Jira: link to ticket
• Link to previous change of the code/bug (if applicable): N/A
• Link to epic if not included in ticket

Testing done

• New code is covered by unit tests
• Describe what the old behavior was prior to the change: This is new functionality so no prior behavior.
• Describe the steps required to verify your changes are working as expected. Exclusively stating 'Specs run' is NOT acceptable as appropriate testing: Ran the service in rails c, no errors 💪🏻
• If this work is behind a flipper:
  • Tests need to be written for both the flipper on and flipper off scenarios. Docs.
  • What is the testing plan for rolling out the feature?: Long term is continue moving code in adhering to LOC requirements, add Flipper, open up Flipper to small percentage of users, monitor.

Screenshots

Note: Optional

What areas of the site does it impact?

No areas, this is a new feature.

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

Requested Feedback

(OPTIONAL)What should the reviewers know in addition to the above. Is there anything specific you wish the reviewer to assist with. Do you have any concerns with this PR, why?

[OptionSelect]

LGTM! 🚀