NoK/EC: Add VA Profile Health Benefits update functionality to vets-api

[wesrowe]

Description

User story

As a Cartography team member, I want to add the vets-api code that can make API calls to the Health Benefits endpoint(s) of VA Profile so that we can request updates to associated persons like Next of Kin and Emergency Contacts.

Notes

• You can send only associatedPersons to update just associated persons
• To remove associated persons, you provide an endDate on the associated person you want to remove
• There is no status endpoint to check

Example success response:

{
  "messages": [
    {
      "code": "HB204",
      "key": "_VHA_ES_UPDATE_SERVICE_INFO",
      "text": "VHA ES Update Service returned message: mdm.cuf.core.messages.Message@70365e72[code=200,key=sucessfully received,text=<null>,severity=<null>,potentiallySelfCorrectingOnRetry=<null>]",
      "severity": "INFO",
      "potentiallySelfCorrectingOnRetry": false
    }
  ]
}

Possible tasks:

Acceptance criteria

• a feature toggle for this new functionality have been created (e.g. - profile_contacts_update_destroy_enabled)
• vets-api has backend client code that can update/destroy associated persons within the VA Profile health-benefit service
• backend client errors are reported to sentry/datadog
• controller methods for the vets-api route /v0/profile/contacts have been created (e.g. - #update,#destroy)
• relevant code has test coverage (e.g. - controller specs, request specs, unit specs)
• swagger/openapi documentation for new endpoint have been updated to match the endpoint's response
• vets-api returns responses according to format determined in #90523

[dcloud]

We'll also need a ticket or two for handling the transaction-status aspect because VA Profile typically has a separate endpoint for checking that a requested change succeeded