99465 implement poa establishment status method in lighthouse api client

[patrick-brown-oddball]

Summary

• Work for this ticket - Implement POA Establishment Status Method In Lighthouse API Client va.gov-team#99465
• I branched off of this ticket - Implement POA Establishment Method In Lighthouse API Client va.gov-team#99310 and branch 99310-Implement-POA-Establishment-Method-In-Lighthouse-API-Client
• I need to add VCR after I have access
• I used this API documentation as guide - https://developer.va.gov/explore/api/benefits-claims/docs?version=current

Related issue(s)

• Implement POA Establishment Method In Lighthouse API Client va.gov-team#99310

Testing done

• New code is covered by unit tests
• Needs VCR tests

Acceptance criteria

• Handle responses, including error responses, following the conventions of sibling endpoint methods

[ryan-mcneil]

I think the checks aren't running because of how the PR it setup. How did you create the PR? It looks weird... compare that to other open PRs and you'll see what I mean. hmm