[sx1278] Major test refactor + GUI test entrypoint

CMakeLists.txt

src/shared/radio/SX1278/SX1278.cpp

src/shared/radio/SX1278/SX1278.h

src/tests/drivers/sx1278/common.h

src/tests/drivers/sx1278/gui/GUI.h

src/tests/drivers/sx1278/test-sx1278-bench-gui.cpp

src/tests/drivers/sx1278/test-sx1278-bench-serial.cpp

src/tests/drivers/sx1278/test-sx1278-bench.cpp

src/tests/drivers/sx1278/test-sx1278-bidir.cpp

src/tests/drivers/sx1278/test-sx1278-mavlink.cpp

src/tests/drivers/sx1278/test-sx1278-rx.cpp

src/tests/drivers/sx1278/test-sx1278-serial.cpp

src/tests/drivers/sx1278/test-sx1278-tx.cpp