CHIRP

Many radios allow receive on frequency ranges that they refuse to transmit on. CHIRP currently has no way to indicate this.
in discussion with Dan Smith, the simplest way to implement this is for the driver to set the "duplex" field to "off" when the user enters anything that leads to an invalid TX frequency on the channel. RadioFeatures.valid_bands will continue to describe the valid RX bands and the UI will continue to enforce these bands for both TX and RX. duplex=="off" will be an additional restriction.

To support this, the automated test system module "run_tests.py" must be modified to treat a response of duplex == "off" as a legal response in all cases, even when the test case would otherwise expect another value.

This issue tracks only the change to run_tests. Driver changes can be made as desired after this change takes effect and can be handled as separate issues.