Process entries with duplicated SV and timestamp in NAV3
Process entries with duplicated SV and timestamp in NAV3

A new sv of the form sv_n (where n is an increasing counter) is
created to store the duplicated entries, as many times as needed.
This is useful for Galileo, where we have different ephemeris
coming from different bands. These have slightly different data.

geospace-code/georinex,scienceopen/pyrinex,geospace-code/georinex