feat: support proxy set buffer bytes

Author: Wim Spaargaren

proxywasm/rawhostcall/rawhostcall.go

@@ -66,6 +66,9 @@ func ProxySetHeaderMapPairs(mapType types.MapType, mapData *byte, mapSize int) t
 //export proxy_get_buffer_bytes
 func ProxyGetBufferBytes(bt types.BufferType, start int, maxSize int, returnBufferData **byte, returnBufferSize *int) types.Status
 
+//export proxy_set_buffer_bytes
+func ProxySetBufferBytes(bt types.BufferType, start int, maxSize int, bufferData *byte, bufferSize int) types.Status
+
 //export proxy_continue_stream
 func ProxyContinueStream(streamType types.StreamType) types.Status