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.

pkg/api/resolver_model_scene.go

@@ -87,6 +87,8 @@ func (r *sceneResolver) Paths(ctx context.Context, obj *models.Scene) (*models.S
 	vttPath := builder.GetSpriteVTTURL()
 	spritePath := builder.GetSpriteURL()
 	chaptersVttPath := builder.GetChaptersVTTURL()
+	funscriptPath := builder.GetFunscriptURL()
+
 	return &models.ScenePathsType{
 		Screenshot:  &screenshotPath,
 		Preview:     &previewPath,
@@ -95,6 +97,7 @@ func (r *sceneResolver) Paths(ctx context.Context, obj *models.Scene) (*models.S
 		Vtt:         &vttPath,
 		ChaptersVtt: &chaptersVttPath,
 		Sprite:      &spritePath,
+		Funscript:   &funscriptPath,
 	}, nil
 }