Events types generated by the source aren't the same as the ones declared in the CRD

[antoineco]

Describe the bug
The event type is read from a header, and that header differs from the values declared in the CRD:

https://github.com/knative-sandbox/eventing-gitlab/blob/bd9856def23300ec1883c55d7a565c585ba6b408/pkg/adapter/receive_adapter.go#L162

https://github.com/knative-sandbox/eventing-gitlab/blob/bd9856def23300ec1883c55d7a565c585ba6b408/config/300-gitlabsource.yaml#L28-L39

Expected behavior

Event types declared in the CRD are the same as the ones emitted by the source.

Additionally, the controller should report the events emitted by a given instance of the source by updating the source's Status.CloudEventAttributes.

To Reproduce
Create any valid instance of GitLabSource and observe the type of incoming events.

Knative release version
v0.18.0 and below

Additional context
Add any other context about the problem here such as proposed priority

/assign