NimBLE does not stop advertising threads on reset_cb

When internal error occurs, controller is reset, while MESH advertising threads are not stopped. This results in controller being out of sync with host.

https://pastebin.com/MQ67ug73

Start by tracing reset_cb and the MESH advertising thread lifecycle described in the issue, then review the controller reset path and the linked pastebin diagnostic. Done means an internal-error reset stops the MESH advertising threads and leaves the controller and host synchronized; no file or test is named in the issue.

Written by the indexing model from the issue text.