Provider verification in KFP Operator events webhook

[grahamia]

Overview
Currently in the run completion data that is sent to the events webhook the "provider" is never validated that it is the correct value, a provider should never be able to send a request for another provider, we should validate as a step in the webhook that the provider is correct.

Technical Details
The request in to the webhook accepts the following JSON:

{
    "pipelineName": "penguin-pipeline",
    "provider": "vai",
    "runConfigurationName": "penguin-rc",
    "runId": "penguin-pipeline-20241125040000990",
    "runName": "penguin-pipeline",
    "servingModelArtifacts": null,
    "status": "succeeded"
}

the provider element needs to verified to ensure it came from that provider.

This task is separate to the main security task of securing the connection from the provider to the KFP Operator webhook (link to issue once raised)