Define an interface to send webhook messages

Once event types defined and user endpoints associated, we need to define an interface to send webhook messages with extra filtering features.

changed milestone to %Webhook-based notification for long-running user tasks [Roadmap - Share]

added Webhooks activity::Implementation priority:Normal labels

assigned to @anlambert

changed title from Define an interface to send webhook message to Define an interface to send webhook messages

mentioned in merge request !3 (merged)

marked this issue as related to swh-web#3955

closed