As a developer I would like to be able to provide an implementation for a specific configuration and payload processing of web-hooks implemented by a specific plugin purchased in the Atlassian marketplace (functionality available only on the server side).

This would allow, through a custom configuration and registration of the web hook, to use specific peculiarities of the plugin installed on the server; such as: not sending a notification for commits/actions performed by a specific user (builder user), those coming from one or more specific branches or any other type of functionality supported by the web-hooks plugin.

This mean we have to design some interfaces to:

1. Webhook provider to participate the web hook lifecycle (to register new one, update existing and so on) given the server URL / branch.
2. Add configuration (maybe again through traits) to be passed to the webhook provided
3. An interface for the Webhook processor to extract the payload informations