Allow OIDC Providers to be available via local socket

[jvanderhoof]

Desired Outcome

The outcome of this PR is to provide a mechanism for a local service to retrieve a list of configured OIDC authenticators.

Note This functionality is intended as a stop-gap for the UI in Conjur Enterprise. The ui socket service will be removed in the near future.

Implemented Changes

This PR includes a couple of changes:

• Refactor the authn-local unix socket server to accept a custom response.
• Enable the /:authenticator/:account/providers route to be served over a local unix socket.
• Refactors authn-local to utilize the generic unix socket service

Connected Issue/Story

CyberArk internal issue link: ONYX-23542

Definition of Done

At least 1 todo must be completed in the sections below for the PR to be merged.

Changelog

• [x] The CHANGELOG has been updated, or
• [ ] This PR does not include user-facing changes and doesn't require a CHANGELOG update

Test coverage

• [ ] This PR includes new unit and integration tests to go with the code changes, or
• [x] The changes in this PR do not require tests

Note

• `authn-local service is tested at the integration level
• The behavior of the Authentication::AuthnOidc::V2::Views::ProviderContext class is well tested with unit tests.
• Additional tests need to be added in the near future.

Documentation

• [ ] Docs (e.g. READMEs) were updated in this PR
• [ ] A follow-up issue to update official docs has been filed here: insert issue ID
• [x] This PR does not require updating any documentation

Behavior

• [ ] This PR changes product behavior and has been reviewed by a PO, or
• [ ] These changes are part of a larger initiative that will be reviewed later, or
• [x] No behavior was changed with this PR

Security

• [ ] Security architect has reviewed the changes in this PR,
• [ ] These changes are part of a larger initiative with a separate security review, or
• [x] There are no security aspects to these changes

[codeclimate[bot]]

Code Climate has analyzed commit 368531e5 and detected 11 issues on this pull request.

Here's the issue category breakdown:

Category	Count
Complexity	6
Style	5

The test coverage on the diff in this pull request is 34.6% (50% is the threshold).

This pull request will bring the total coverage in the repository to 89.7% (-1.7% change).

View more on Code Climate.