Expose target_iid in Events API

changelogs/unreleased/13247-api_project_events_target_iid.yml

+---
+title: Expose target_iid in Events API
+merge_request: 13247
+author: sue445

doc/api/events.md

@@ -302,6 +302,7 @@ Example response:
     "project_id":1,
     "action_name":"opened",
     "target_id":160,
+    "target_iid":160,
     "target_type":"Issue",
     "author_id":25,
     "data":null,
@@ -322,6 +323,7 @@ Example response:
     "project_id":1,
     "action_name":"opened",
     "target_id":159,
+    "target_iid":159,
     "target_type":"Issue",
     "author_id":21,
     "data":null,

lib/api/entities.rb

@@ -483,7 +483,7 @@ module API
 
     class Event < Grape::Entity
       expose :title, :project_id, :action_name
-      expose :target_id, :target_type, :author_id
+      expose :target_id, :target_iid, :target_type, :author_id
       expose :data, :target_title
       expose :created_at
       expose :note, using: Entities::Note, if: ->(event, options) { event.note? }