✨ (phase 2 plugins): enable external plugins to specify metadata and examples

[everettraven]

Description of the change

Update the external plugin implementation to allow external plugins to specify metadata and examples for their plugin:

• Add the UpdateMetadata function to the init, create api, create webhook, and edit subcommands
• Add helper functions for common functions related to this process
• Uses a default metadata string if the external plugin does not provide any
• Add unit tests to verify the change and helper functions work as expected

Add a new helper function called makePluginRequest for making requests to external plugins. This makes the code for making a request to external plugins easier to reuse and prevents code duplication.

• Update existing helper functions to use this new helper function for making requests to external plugins

Motivation for the change

This change allows external plugins to specify the metadata and examples that are provided to a Kubebuilder CLI user when they request the help text for a plugin. This gives Kubebuilder CLI users the same native plugin feeling for external plugins.

For more information see issue #2690

Additional Context

resolves #2690

[k8s-ci-robot]

Hi @everettraven. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[everettraven]

The APIDiff failure is expected as there was a change made to the external plugin API.

[camilamacedo86]

Great 🥇

[camilamacedo86]

/ok-to-test
/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: camilamacedo86, everettraven

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [camilamacedo86]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[everettraven]

@camilamacedo86 The APIDiff failure is expected since the external plugin API was changed for this. Would you be able to override this check so it can merge? Thanks!