Support lalalambda's lambda()

[devinivy]

Support srv.lambda() provided by lalalambda.

References:
https://github.com/hapipal/lalalambda/blob/master/API.md#serverlambdalambda
https://github.com/devinivy/lalalightbulb/blob/master/lib/.hc.js