Host stuck in connecting state after timeout

[rojer]

Occasionally we get host stuck in a connecting state, where a connection that timed out has not been cleaned up.
In fact, in the post-mortem memory dump examination it looks exactly as the condition described in this TODO: ble_gap_master.exp_set is 0, but cb and cb_arg are still set, suggesting that conn_complete never arrived.
If would be nice to have the remedial action implmeneted as described - an additional timeout and a controller reset.

FWIW, platform is ESP32-C3 with BLE_EXT_ADV enabled. And there's a suspicion that it only occurs when BLE_EXT_ADV is enabled, since it wasn't happening before.

[rojer]

cc @ccollins476ad for context of 6418926, maybe (blast from the past!)