Plugin hooks (#1452)

* Refactor session and plugin code
* Add context to job tasks
* Show hooks in plugins page
* Refactor session management

pkg/plugin/examples/js/js.yml

@@ -24,4 +24,35 @@ tasks:
     description: Sleeps for 100 seconds - interruptable
     defaultArgs:
       mode: long
-      
+hooks:
+  - name: Log scene marker create/update
+    description: Logs some stuff when creating/updating scene marker.
+    triggeredBy: 
+      - SceneMarker.Create.Post
+      - SceneMarker.Update.Post
+      - SceneMarker.Delete.Post
+      - Scene.Create.Post
+      - Scene.Update.Post
+      - Scene.Destroy.Post
+      - Image.Create.Post
+      - Image.Update.Post
+      - Image.Destroy.Post
+      - Gallery.Create.Post
+      - Gallery.Update.Post
+      - Gallery.Destroy.Post
+      - Movie.Create.Post
+      - Movie.Update.Post
+      - Movie.Destroy.Post
+      - Performer.Create.Post
+      - Performer.Update.Post
+      - Performer.Destroy.Post
+      - Studio.Create.Post
+      - Studio.Update.Post
+      - Studio.Destroy.Post
+      - Tag.Create.Post
+      - Tag.Update.Post
+      - Tag.Destroy.Post
+    defaultArgs:
+      mode: hook
+    
+