[feat] Validate ClientId

[gnought]

Based on the MQTT 3.1.1 spec:

The ClientId MUST be a UTF-8 encoded string as defined in Section 1.5.3 [MQTT-3.1.3-4].

The Server MUST allow ClientIds which are between 1 and 23 UTF-8 encoded bytes in length, and that contain only the characters

"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" [MQTT-3.1.3-5].

The ClientId should fall within the allowed character ranges, we could follow and offer an option to override the behaviour.

[robertsLando]

Isn't this already supported?

Check maxClientsIdLength https://github.com/moscajs/aedes/blob/master/docs/Aedes.md#new-aedesoptions--new-aedesserveroptions

[gnought]

I mean the ClientId should be within the mentioned characeter set 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ No spaces, no hypens, no dash.

[robertsLando]

@gnought Oh ok sorry I misunderstand what you wrote. In this case I would prefer to create an option for sure, but I'm not sure I would make it respect the standard by default, I think that this would break many existing instances. I would prefer an option like: validateClientId that by default is false