chore: Adds CoudEvents when a ScaledObject scales a workload from/to zero or one

[neelanjan00]

Checklist

• [x] When introducing a new scaler, I agree with the scaling governance policy
• [x] I have verified that my change is according to the deprecations & breaking changes policy
• [x] Tests have been added
• [x] Changelog has been updated and is aligned with our changelog requirements
• [x] A PR is opened to update our Helm chart (repo) (if applicable, ie. when deployment manifests are modified)
• [x] A PR is opened to update the documentation on (repo) (if applicable)
• [x] Commits are signed with Developer Certificate of Origin (DCO - learn more)

Relates to #3527

[tomkerkhove]

Can you open a PR for our docs as well please?

[zroubalik]

@neelanjan00 any update on this please?

[SpiritZhou]

eventEmitter.Emit() will emit a k8s event at the same time. Replacing the recorder with eventEmitter and r.Recorder.Event() with eventEmitter.Emit() is better than passing an eventEmitter as a new parameter. Alternatively, we could pass an eventEmitter as a new parameter and delete the recorder once all r.Recorder.Event() calls have been replaced.

[tomkerkhove]

We are planning release on Thursday, any chance we can incorporate the feedback?

[neelanjan00]

Hey @tomkerkhove, @zroubalik sorry for not being active on this! I am presently occupied with some office work so not able to put time away for this, not sure if I will be able to add the E2E tests on time for the release.

[tomkerkhove]

No worries!