Rayhunter uses a mixture of spawn and spawn_blocking, then also does
some blocking operations inside of async code.
Move everything to async. This allows us to use the single-threaded
runtime.
Now the binary is 100kB smaller, and the memory usage also improved by
~100kB on tplink.
Add support for the Tmobile TMOHS1, a Wingtech CT2MHS01-based hotspot
with a Qualcomm mdm9607. The TMOHS1 has no screen, only 5 LEDs, two of
which are RGB.
