Store L3 data with meaningful sonde_id (HALO_20240811_1...)

[ninarobbins]

Right now sonde_id is a number that doesn't allow to organize data based on flight day.

[Geet-George]

The sonde_id should simply work as a unique identifier. Meaning in its syntax is not expected. See also conversation in #127

If the user wants sonde from a particular day, they can always use interpolated_time var in L3, or other vars like flight_id. The sonde_id is not meant for subsetting uses.