Expose version number of operator

[calebschoepp]

It would be nice to be able to fetch version number of controller via a http endpoint (or some other appropriate way). (e.g. for displaying in spin k8s version command output).

[calebschoepp]

Previous Discussion

@endocrimes

I think this would need to rely on introspecting the deployment - As much as I kind of want an api for validating pre-flight checks (i.e is a runtime class installed? etc) eventually, there isn't a good standard way of doing this 😅 - and it gets harder if we end up decoupling the operator from namespaces 😢

CC @rajatjindal