Add Handy / Funscript support (#1377)

* Add funscript route to scenes

Adds a /scene/:id/funscript route which serves a funscript file, if present.

Current convention is that these are files stored with the same path, but with the extension ".funscript".

* Look for funscript during scan

This is stored in the Scene record and used to drive UI changes for funscript support.

Currently, that's limited to a funscript link in the Scene's file info.

* Add filtering and sorting for interactive
* Add Handy connection key to interface config
* Add Handy client and placeholder component.

Uses defucilis/thehandy, but not thehandy-react as I had difficulty integrating the context with the existing components.

Instead, the expensive calculation for the server time offset is put in localStorage for reuse.

A debounce was added when scrubbing the video, as otherwise it spammed the Handy API with updates to the current offset.

graphql/documents/data/scene-slim.graphql

@@ -11,6 +11,7 @@ fragment SlimSceneData on Scene {
   organized
   path
   phash
+  interactive
 
   file {
     size
@@ -31,6 +32,7 @@ fragment SlimSceneData on Scene {
     vtt
     chapters_vtt
     sprite
+    funscript
   }
 
   scene_markers {