altosui: Support raw telemetry from TeleDongle

Use raw telemetry frames when TeleDongle supports them, this involves
parsing the hex dump of the packet instead of having teledongle take
the packet apart. Only the legacy format is working at this point; the
altos bits for the new split telemetry frames is not written yet.

Signed-off-by: Keith Packard <keithp@keithp.com>