kubectl: fix plugin lookup with positional arguments

[sttts]

What type of PR is this?

/kind bug

What this PR does / why we need it:

Without this PR, a plugin is found for kubectl create foo --flags, but kubectl create foo bar --flags is not even though kubectl-create-foo exists.

This PR fixes the plugin search algorithm by not looking for an exact match, but letting it try from longest to shortest plugin command, but longer than the command (create) that is extended.

Note: kubectl create is explicitly a command whose subcommands can be overwritten (it's the only one).

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?

Make kubectl find `kubectl-create-subcommand` plugins also when positional arguments exists, e.g. `kubectl create subcommand arg`.

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

[k8s-ci-robot]

Please note that we're already in Test Freeze for the release-1.30 branch. This means every merged PR will be automatically fast-forwarded via the periodic ci-fast-forward job to the release branch of the upcoming v1.30.0 release.

Fast forwards are scheduled to happen every 6 hours, whereas the most recent run was: Sun Mar 31 14:12:16 UTC 2024.

[soltysh]

I had a long conversation with Stefan about this topic. tl;dr is this is not exposing the create plugins shadowing mechanism to anything unexpected. It only addresses a problem where a user wants to use a positional argument in their create plugin. For example, kubectl create myjob testjob should invoke kubectl-create-myjob rather than kubectl-create myjob-testjob, which makes the mechanism identical to our current kubectl create subcommands which accepted, even require user to pass the name of the newly created resource as the first argument - a positional one.

/triage accepted
/priority important-longterm

[soltysh]

/lgtm
/approve

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 18f099f4fdb34f2569d1b33d5e2c3992c71229f1

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: soltysh, sttts

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