[10-10CG] Add paginated facilities endpoint to CG controller

[coope93]

Summary

• This work is behind a feature toggle (flipper): NO
• The front end work that uses this endpoint is behind a flipper toggle, so the backend does not have the toggle.
• The lighthouse api returns pagination information, but the existing Facilities/V1/Client did not return the full response object. This PR adds a method to the client to return the full response, as well as a new caregivers route that returns the facilities list with pagination metadata.
• Update client to handle no data key being returned by the lighthouse api. This is technically possible if you request a page that is outside of the page range. My forthcoming vets-website changes will eliminate this issue from the front end, but the endpoint could technically be called with page 5000 for a result set of 1.

Related issue(s)

• [FE] 10-10CG - Facilities selection: Search Results and "show more" link va.gov-team#70846

Testing done

• New code is covered by unit tests
• Added spec for Facilities/V1/Client

What areas of the site does it impact?

10-10CG

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

I updated our existing controller spec for this route. I would eventually like to replace that spec with a request spec, but at this moment I didn't want to take on the scope of that work unless someone really wants me to.

[coope93]

The new facilities method does not require initializing a claim. These are the only other two exposed routes in this controller. I think this also makes this initialize_claim logic more obvious.

[coope93]

Added new facilities route, and moved the post declaration here. This is functionally the same as before, just easier to read.

[coope93]

If no facilities are returned, the lighthouse api does not return a data key or object. This handles that scenario by setting it to an empty array.

[Mitch-A6]

💅 This wasn't an issue when we were pulling Facilities for specific States, but definitely comes in to play now. Nice!

[coope93]

As mentioned above, I'd like to eventually move these to request specs.

[coope93]

I deleted these and moved them to the request spec.

[ryan-mcneil]

@coope93 Please pull master to clear up the CVE