[CAT-1593] Fix missing webhook type and evidence folder webhook (#138)

* Add workflow_timeline_file

The resource type was missing, we need it in order to parse
the webhook payload using the official client libraries.

* Add evidence folder created webhook types

schemas/webhooks/definitions.yaml

@@ -62,6 +62,8 @@ webhook_event_resource_type:
     - workflow_run
     - workflow_task
     - watchlist_monitor
+    - workflow_timeline_file
+    - workflow_run_evidence_folder
 
 webhook_event_type:
   type: string
@@ -83,6 +85,7 @@ webhook_event_type:
     - report.completed
     - workflow_timeline_file.created
     - workflow_signed_evidence_file.created
+    - workflow_run_evidence_folder.created
 
 webhook_url:
   type: string