[Feature request] Basic TX support

[AsciiWolf]

I know that Gqrx is a RX (not TX) focused SDR software, however it could also be used as a basic TX SDR as well since it already supports multiple devices with TX abilities. Good start could be adding some basic AM/SSB and NFM modulators.

Feel free to close this ticket if you believe that it is not a good idea. :-)

Thanks!