[Feature] cookie support

[AntonioSun]

Need to be able to return mock HTTP cookies.

Please consider. thx.

[Ananto30]

@AntonioSun will consider surely, but recently I am very busy, will look into soon. And if you consider contributing, would be great 😃

[AntonioSun]

Thanks for your answer @Ananto30,

Normally I'd give a week or two for the author to reply, but this time, after thinking and planning for a whole night last night, this morning I jumped into action without checking my email.
But I went to a different direction. You can take a look here -- https://github.com/AntonioSun/mockserver
Totally based on your work, but uses the json format from that of https://mock-server.com/, which I believe will attract a broader audience. I'm only taking a breath and checking my emails now, after I've finish it.

I have lots planned for further improvements, and you're very welcome to give it a try.