Feature Request: Expand bridge with Session Expiry Interval (MQTT 5.0)

[JSchy65]

The MQTT 5.0 specification defines in 3.1.2.11.2 the Session Expiry Interval for the CONNECT properties.

Actual (2.0.18), the Mosquitto Bridge sends no Session Expiry Interval value within the CONNECT Properties.

MQTT 5.0 spec:
"If the Session Expiry Interval is absent the value 0 is used. If it is set to 0, or is absent, the Session ends when the Network Connection is closed."

If the Session Expiry Interval is not sent, that leads to loos of messages in case of communication breakdown, because the broker where the connect was made to, will remove all messages in that case. That behaviour is described in issue #2793.

In my opinion, without the implementation of the Session Expiry Interval for the CONNECT, the use of the Mosquitto Bridge with MQTT 5.0 in a remote scenario, where the both MQTT brokers are connected e.g. via internet and where you have to expect communication breaks, is not possible in a meaningful way, because lots of messages will be lost in case of communication breakdown.

See also:
#1632
#2424

MQTT 5.0 see:
https://docs.oasis-open.org/mqtt/mqtt/v5.0/os/mqtt-v5.0-os.html