Retry reloads for the Band/Mode set operation

Whenever we update bands or modes and we get a successful reply from the module, we will right away do a get operation to load the settings from the modem. We will now compare them to the ones we requested, and if they're different, schedule the reload operation in 1s so that we check again.

This is to support without problems modems that require time to actually apply the setting after they've accepted the request, e.g. in QMI modems using NAS Set System Selection Preference.