Make Network Socket in UdpPubSubConnection reachable

[MaxKarl31]

Type of issue

• [ ] Bug
• [X] Enhancement
• [ ] Compliance
• [ ] Question
• [ ] Help wanted

Current Behavior

At the moment when using an UdpPubSubConnection one is not able to configure the used Socket. However one might want to adjust some settings of it and change them (e.g. the size of the ReceiveBuffer.

Expected Behavior

It should be possible to access the Socket of an UdpPubSubConnection

Steps To Reproduce

No response

Environment

No response

Anything else?

No response

[mregen]

@mrsuciu, is the socket exposed by the MQTTNet client library?