Flipper/Sub-GHz/ext

Some changes I made to the frequency scanner settings.

Officially supported frequencies are 300-348 MHz, 387-464 MHz, and 779-928 MHz (from CC1101 chip docs)
Unofficially supported frequencies are 281-361 MHz, 378-481 MHz, and 749-962 MHz (from YARD Stick One docs)

NOTE: Going outside the supported frequencies may DAMAGE YOUR FLIPPER.
Please understand what you're doing if trying to break out of official frequencies.

You'll need to edit some code and recompile if you want to break outside the officially supported frequencies. (Hint here...)

The file is found under Flipper -> ext -> subghz -> assets

CAUTION within 402-408 range! Medical devices can operate here.