FI-575 Add informational messages from validators to the UI

[okeefm]

Previously, some messages from the HL7 validator that were at an "informational" level (things like not adhering to recommended valueset bindings, incorrect display names for codes, etc.) were being displayed as "warnings". This PR moves those messages to a separate level with its own icon in the UI, to keep people from stressing over messages that don't rise to the warning level.

The test result list page, indicating the presence of informational messages

The test result details page, displaying those messages

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[Jammjammjamm]

I'm not a fan of that info icon, but this seems to work fine.

However, it really exposes how we need to update our validation messages to indicate which resource they're associated with now that we're validating multiple resources.

[okeefm]

@arscan both @Jammjammjamm and I are not super happy with the icon being used for the information, but we can't find a better one in the Open Iconic iconset. Ideally I'd use something like this: https://fontawesome.com/icons/info-circle?style=solid, but open iconic doesn't seem to have an equivalent. Thoughts?