Initial opensearch backed v2 endpoint

[JPrevost]

Why are these changes being introduced:

• Being able to connect to OpenSearch from TIMDEX API is a building
  block towards implementing the v2 API

Relevant ticket(s):

• https://mitlibraries.atlassian.net/browse/RDI-27

How does this address that need:

• creates a toggleable v2 version of the v1 endpoints
• passes clients into the endpoints to allow v1 and v2 to use different
  clients while (for now) sharing most of the querying logic

Document any side effects to this change:

• DockerFile, composer, and makefile are not yet updated to reflect
  being backed by both ES and OS at the same time.
• GraphQL is only available on the V1 endpoint
• The v2 endpoint this introduces is largely the same spec as v1 and
  does not reflect the future needs of the v2 endpoint. It essentially
  allows v1-like functionality to be backed by opensearch. We have
  additional tickets open to plan and implement the actual v2 endpoint.

Requires Database Migrations?

NO

Includes new or updated dependencies?

YES

[jazairi]

I think this approach makes sense, and it should make it easier for us to deprecate v1 should we want to do that down the road. I don't think that some of the CodeClimate suggestions are applicable here (e.g., the DRY warnings), but I would recommend cleaning up the minor stuff (trailing whitespace, empty lines, instance_of?, parenthesis) before we merge this.