add fetch options

[gormonn]

add fetch options to pass headers

In some cases we need to pass api-key or something else.

For example:

app.get("/WebClient/*", 
  async (req, res, next) => {
    res.locals.fetchUrl = `http://someapi.ru/WebClient/${req.params[0]}?${encodeQuery(req.query)}`;
    res.locals.options = { headers: req.headers }
    next();
  },
  fileCacheMiddleware({ cacheDir, maxSize: 10 * 1024 * 1024 * 1024 * 1024 }),
  (req, res) => {
    res.set({
      "Content-Type": res.locals.contentType,
      "Content-Length": res.locals.contentLength
    });
    res.end(res.locals.buffer, "binary");
  }
);

[julianrubisch]

Great, thanks!

I haven't looked in here for a while, and just to make sure we don't break anything - could you add a test?