feat: generic webhook

[arbreezy]

Closes # #133

📑 Description

✅ Checks

• My pull request adheres to the code style of this project
• My code requires changes to the documentation
• I have updated the documentation as required
• All the tests have passed

ℹ Additional Information

I have created a few Results functions in a similar fashion with k8sgpt resources, introduced two status fields for Results

1. Lifecycle -> to show the lifecycle of a Result CR {created, updated, historical}
2. Webhook -> to show the sink endpoint that is configured in K8sGPT CR for each Result

In regard to emitting messages I depend on the status of each Result to send its payload to the specified sink while also updating/cleaning up the status if needed

Sink is an interface that has two signatures Configure and Emit which may be useful if we want to add more sink types ( discord, etc..)

We also cleanup the statuses of Results when Sink is not defined anymore in K8sGPT CR

PS: I didn't consider a fanout solution cause I haven't seen such need to configure more than one integrations.

[AnaisUrlichs]

Could you please update the following page in the docs with the minimum information needed for people to

1. know that there is a webhook option
2. understand how to make use of it
   Link to docs:
   https://docs.k8sgpt.ai/reference/operator/overview/#customising-the-operator

[AlexsJones]

Left some messages inline

[arbreezy]

Slack message looks like this,