feat:Contact Points New APIs

**Is your feature request related to a problem? Please describe.**
The API used for Contact points is getting replaced using the K8s style. Some of the API calls we are using are full on deprecated now.

Ideally we should wait till v1 is cut but the current pattern is as follows:

DELETE /apis/notifications.alerting.grafana.app/v1beta1/namespaces/{namespace}/receivers/{name}

Since this is very actively changing we should allow a user override to set the API version

**Describe the solution you'd like**

Replace the legacy API.