* add tests for webhooks
* improve error handling when context does not contain webhook manager
* add logging to worker and fix nesting error overwrite
* remove enable and disable methods in favor for update method
* move data in jwt from subject claim to custom `data` claim
* add event in jwt to custom `evt` claim
* change webhook trigger to only fire once per hook (was once per subscribed event in hook before)
Closes#692
* add webhooks settings to config
* add webhooks entity for database
* add endpoints for webhooks
* add worker for asynchronously executing webhooks
* add trigger for events to user change/create/delete users/emails
Closes#692
