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.

ui/v2.5/src/components/Help/Manual.tsx

@@ -15,6 +15,7 @@ import SceneFilenameParser from "src/docs/en/SceneFilenameParser.md";
 import KeyboardShortcuts from "src/docs/en/KeyboardShortcuts.md";
 import Help from "src/docs/en/Help.md";
 import Deduplication from "src/docs/en/Deduplication.md";
+import Interactive from "src/docs/en/Interactive.md";
 import { MarkdownPage } from "../Shared/MarkdownPage";
 
 interface IManualProps {
@@ -92,6 +93,11 @@ export const Manual: React.FC<IManualProps> = ({
       title: "Dupe Checker",
       content: Deduplication,
     },
+    {
+      key: "Interactive.md",
+      title: "Interactivity",
+      content: Interactive,
+    },
     {
       key: "KeyboardShortcuts.md",
       title: "Keyboard Shortcuts",