Fix authenticated media loading for Tauri/WebKit environments

- Add useAuthenticatedMediaUrl hook that fetches media with auth headers
- Add AuthenticatedMedia, AuthenticatedAvatarImage components
- Update downloadMedia and downloadEncryptedMedia to accept access token
- Update all media components to pass access token for auth media
- Fix 401 errors on Matrix servers requiring authenticated media (v1.11+)

This fixes media loading in Tauri desktop apps where service workers
may not work reliably for cross-origin authenticated requests.

src/app/components/message/content/VideoContent.tsx

@@ -82,11 +82,12 @@ export const VideoContent = as<'div', VideoContentProps>(
     const [srcState, loadSrc] = useAsyncCallback(
       useCallback(async () => {
         const mediaUrl = mxcUrlToHttp(mx, url, useAuthentication) ?? url;
+        const accessToken = mx.getAccessToken();
         const fileContent = encInfo
           ? await downloadEncryptedMedia(mediaUrl, (encBuf) =>
-              decryptFile(encBuf, mimeType, encInfo)
+              decryptFile(encBuf, mimeType, encInfo), accessToken
             )
-          : await downloadMedia(mediaUrl);
+          : await downloadMedia(mediaUrl, accessToken);
         return URL.createObjectURL(fileContent);
       }, [mx, url, useAuthentication, mimeType, encInfo])
     );