In 8.3 mode, ensure that 25 and 75Khz channels can be tuned using the abbreviated syntax (eg 118.02 for 118.025). As part of this, add test coverage of the CommRadio for basic and 8.3- mode operation.
Also includes false GS lobe tests
Complex cases still to be added, but this tests the basic reception.
Still needs ILS and GS tests, but starting to be useful already.
