Improve WriteMessage fast path
Improve WriteMessage fast path

Restructure to avoid messageWriter allocation.

helight/helight_code,your-org/websocket,helight/helight_code,helight/helight_code,helight/helight_code,y3llowcake/websocket,helight/helight_code,helight/helight_code,helight/helight_code,helight/helight_code,gorilla/websocket,helight/helight_code