Built-in Webhooks should be configurable at project level

The built-in webhooks shipped since Bitbucket 5.4 do not cover all the use cases  handled by the predecessor plugin Web Post Hooks for Bitbucket Server

The built-in webhook functionality should be extended to cover:
Use case 1: Project wide webhook configuration
Use case 2: Ability to customize the request body, for example per MS Teams specifications to send notifications.