G6/G7 backfill implementation

[charlesstyves]

Loop and Trio seems to now be able to backfill datas from G6/G7.

Don't know how much work it could need to be implement in iAPS too, but could be great feature.

Real big thanks for all of your works!

[Jon-b-m]

@charlesstyves can you show me the relevant PR, please?

[charlesstyves]

I guess this is the good one :

nightscout/Trio@a0c9e79

[Jon-b-m]

@charlesstyves Ok I will take a look at this 👍and test it