[feat] Move mqtt parser to server-factory

[robertsLando]

Based on this: #2 (comment)

I was also thinking about another idea, I would like to move the mqtt parser to the server factory, so the client will always receive plain mqtt, in that case I would create another function for example handleMqtt that will accept a plain mqtt stream instead (along with connection details)

@mcollina What do you think? Everytime I look into client.nextBath I think that we could do something better, do you have any suggestion?

[mcollina]

I don't think it's possible to do anything different and keep things performant

[robertsLando]

Could you better explain the reason why this moscajs/aedes#519 solution could slow down aedes? I think it would implement the stream parsing in the 'aedes' way (by using a stream), and I don't understand what's the downside of this

[mcollina]

Streams are slow and in this specific case unnecessary overhead.

[robertsLando]

I always tought that streams were the reason behind aedes good performances 😆 Thank you @mcollina for the explanation!