Feature Request: Expose HTTP Max Headers Size Configuration

Problem

We're migrating mope.io (a high-traffic browser game) to uWebSockets.js for better performance, but we're hitting header size limits due to a required large cookie.

Use Case

• Application: mope.io - a popular browser-based multiplayer game
• Traffic: High-volume real-time gaming traffic
• Issue: We have a required cookie FCCDCF (up to 3KB) mandated by premium advertising partners
• Impact: Players can't connect when this cookie is present due to header size limits

Current Situation

• Migration to uWS.js has been excellent for performance
• Everything works perfectly except for this header size limitation
• The cookie cannot be removed or significantly reduced

Proposed Solution

Expose the existing C++ UWS_HTTP_MAX_HEADERS_SIZE configuration in the JavaScript bindings:

const app = uWS.App({
  maxHeaderSize: 16384, // 16KB to handle large cookies
  // ... other options
});