Expose Kind field for Consul Service Registrations

[allisonlarson]

Description

Adds the Kind field to the service block in the jobspec, and allows Consul services to be registered with the Consul Kind type manually. Previously this was only set when using a defined type of Consul Connect gateway, but with the new change, it can be specified on the service itself. If both values (kind and a consul connect gateway) are defined, the service will use the Consul Connect Gateway.

Testing & Reproduction steps

Add kind to jobspec, observe the gateway specified for the service in Consul.

Links

internal Ref https://hashicorp.atlassian.net/browse/NMD-702

Contributor Checklist

• Changelog Entry If this PR changes user-facing behavior, please generate and add a
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• Testing Please add tests to cover any new functionality or to demonstrate bug fixes and
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  change requires notes within the upgrade guide.

Reviewer Checklist

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[tgross]

LGTM! (Once the test gets fixed)

[aimeeu]

Thanks for updating the docs! I left a tiny suggestion so that the text matches our style guide.

[tgross]

LGTM!