Add simple hamlib server functionality

[csntechnologies]

Hi All. Could simple hamlib server support be added? In this way SDRConsole would appear as a hamlib server to handle setting/getting the frequency and mode.

You would start a TCP server and repond to only four command, sent in plain ASCII:
F XXX = set frequency to XXX in MHz
f = respond with current frequency
M XXX = set mode to XXX (FM,USB,etc)
m = respond with current mode

Full details are here: https://hamlib.sourceforge.net/html/rigctld.1.html

Appreciate it!

Keith