Have location tracking in mobile-config track (OLD)

[kurotych]

Additional feature to previous PR: #902

Add migration to back fill data.
usage
./target/debug/mobile-config -c mobile-config.toml migrate-mobile-tracker file.csv

Migration steps:

1. Fill mobile_radio_tracker asserted_location from mobile_hotspot_infos
2. Read data from csv report. Fill mobile_radio_tracker.asserted_location_changed_at if location from csv and in mobile_hotspot_infos table matches

[bbalser]

What is the thinking about making this None? The first time we see a radio, this field will be null and how do you envision clients working with it?

[kurotych]

What is the thinking about making this None?

My logic is next: At the beginning it is None because we don't have information about previous time when asserted_location was changed.

The first time we see a radio, this field will be null and how do you envision clients working with it?

I expect clients (or functions that use tracked mobile radio table) will handle None by their own logic.
Otherwise, if we hardcode some value here, we don't give an option for the clients.