Remove references to private validator functions

[ljtucker]

Summary

Updated the reference resolution test to use the public validator service functions, rather than calling the private functions directly. Should result in no change in behavior

For proof see the following two screenshots of a validation test (2.11.10) performing identically in both production and locally (after changes):

• NOTE: Most of the tests in this kit fail on a "Unknown code in value set" error when running locally, before and after my changes. Screenshot of local run before changes added as proof

Local run before changes:

Local run after changes:

Production run:

[karlnaden]

You don't have to get the validator, you can use the resource_is_valid? DSL method directly

resource_is_valid?(resource:, profile_url: target_profile, add_messages_to_runnable: false)

See the US Core version: https://github.com/inferno-framework/us-core-test-kit/blob/main/lib/us_core_test_kit/reference_resolution_test.rb#L170

[karlnaden]

ran the tests and confirmed that it works after the update