Make the error slightly more readable

[soltysh]

What type of PR is this?
/kind cleanup
/sig cli
/priority important-longterm

What this PR does / why we need it:
It may happen (usually when invoking patch operation) that the Kind and/or Name will be empty, in those cases we're getting nasty:
The "" is invalid

This fixes the error to slightly more readable form:
The request is invalid

Special notes for your reviewer:
/assign @juanvallejo

Does this PR introduce a user-facing change?:

NONE

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: soltysh

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[juanvallejo]

/lgtm

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