FI-2429: migrate to HL7 validator wrapper

[dehall]

Summary

Migrate from the inferno validator wrapper to the HL7 validator wrapper:

• Inferno validator wrapper is commented instead of completely removed in case someone wants the UI again
• Bumped inferno_core gem
• Ignore message "URL value does not resolve"
• Remove the url field from the validator definition block since we are standardizing on just the default FHIR_RESOURCE_VALIDATOR_URL env var now
• This IG does not seem to be published that I can see, so the validator definition block points to the local file. This should be the same filename as is currently deployed so no special action needed there
• Convert validator response to OperationOutcome in the reference_resolution test

Testing Guidance

I'm not sure this test kit can actually be run successfully since I'm getting purple errors on prod. https://inferno.healthit.gov/suites/c19-vci/bOoYIoiWyZV#1

[dehall]

@Jammjammjamm requesting your review on this one because of the purple errors, hoping you know more about how to get this test kit to run

[Jammjammjamm]

The minimum version of core in the gemspec needs to be bumped to a version that supports the new validator.

[dehall]

Updated to the latest as of today, 0.4.37. I didn't catch that before so I'll update that on the other test kits too.