feat: update character images for Tekken 8 and enhance pack management

- Updated character images for Tekken 8, including Jin, Jun, Kazuya, and others.
- Introduced a new pack configuration system to manage character packs from a Gitea instance.
- Added types for pack management, including PackCharacter, PackManifest, and PackRegistry.
- Implemented functions to register and unregister installed packs, allowing dynamic character loading.
- Enhanced the character image retrieval system to support both bundled and installed packs.

src/extension/index.ts

@@ -11,4 +11,5 @@ export default async (nodecg: NodeCGServerAPI) => {
   await import('./example.js');
   await import('./startgg.js');
   await import('./challonge.js');
+  await import('./pack-manager.js');
 };