[REFACTOR] webhook.Handler interface

models/fixtures/webhook.yml

@@ -3,6 +3,7 @@
   repo_id: 1
   url: http://www.example.com/url1
   http_method: POST
+  type: forgejo
   content_type: 1 # json
   events: '{"push_only":true,"send_everything":false,"choose_events":false,"events":{"create":false,"push":true,"pull_request":false}}'
   is_active: false # disable to prevent sending hook task during unrelated tests