knx-listener: Add KNX-Source address to logs

### Use Case

Having the source-address of the KNX-Device in the logs for successful matched group addresses help debugging a lot, since you can filter the logs easily for all telegrams sent from one device.

### Expected behavior

I would like to see something like:
`2026-06-23T09:23:01Z D! [inputs.KNXListener] Matched GA "0/0/6" from source "1.1.250" to measurement "WeatherStation Wind Speed" with value 9.35 m/s`

### Actual behavior

Currently a log entry looks like this:
`2026-06-23T09:23:01Z D! [inputs.KNXListener] Matched GA "0/0/6" to measurement "WeatherStation Wind Speed" with value 9.35 m/s`

### Additional info

_No response_

Start at the knx-listener implementation and locate the debug log for successfully matched group addresses. Trace the matched telegram data to confirm the KNX source address is available, include it in that log, and verify the expected message using the listener's existing tests or a representative run.

Written by the indexing model from the issue text.