`reconnect()` loses QoS on subscribed topics

The class-level variable `_subscribed_topics` is used to track what we're interested in:
https://github.com/adafruit/Adafruit_CircuitPython_MiniMQTT/blob/bf47a0e613235a97346ab0f7b20d727d666c2227/adafruit_minimqtt/adafruit_minimqtt.py#L244

In `subscribe()`, the subscription is noted in the class-level variable (nit: `list(set(...` to deduplicate):
https://github.com/adafruit/Adafruit_CircuitPython_MiniMQTT/blob/bf47a0e613235a97346ab0f7b20d727d666c2227/adafruit_minimqtt/adafruit_minimqtt.py#L837-L840

In `reconnect()`, subscriptions are re-established... but lo, they don't have any way to know `qos`, so they can't re-subscribe with their original QoS.
https://github.com/adafruit/Adafruit_CircuitPython_MiniMQTT/blob/bf47a0e613235a97346ab0f7b20d727d666c2227/adafruit_minimqtt/adafruit_minimqtt.py#L970-L975

Read adafruit_minimqtt/adafruit_minimqtt.py at the _subscribed_topics definition and the subscribe() and reconnect() methods referenced in the issue. Trace how subscribe() records topics and how reconnect() restores them. Done means reconnect() re-subscribes each topic with the QoS originally provided to subscribe().

Written by the indexing model from the issue text.