feat(contact-point): support retrieval by name

[Saurus119]

trafficstars

• Adds support for retrieving a contact point by its exact name.
• If multiple contact points share the same name, the method will return all matching contact points in a list.
• This can occur, for example, when an alert rule uses contact points that implement multiple actions. In Grafana’s UI, such contact points are grouped by name, but they are stored as separate contact points in the backend.