Pulling kafka/service registry validators into SDK

[wtrocki]

Hi

I have noticed that we have some of the validation functions nicely organized in the kafka/registry folders.
It will be good if we actually make them part of the SDK for others to reuse - like kafka name/registry name etc.

Same could be good for status code/error code mappings etc.

[wtrocki]

Related:
Apicurio/srs-fleet-manager#61
https://github.com/pmuir/terraform-provider-rhoas

CC @craicoverflow @pmuir

[craicoverflow]

I have noticed that we have some of the validation functions nicely organized in the kafka/registry folders.

These validators in their current form are highly specific to Cobra APIs.

We could pull them into the SDKs but simplified a bit (there would be no need to pass an interface{} type - then the Cobra validators could wrap these.

[craicoverflow]

Same could be good for status code/error code mappings etc.

I think that the error helpers are specific to the CLI and probably the currently returned error is enough for the client to handle it in its own way.