Use external engine sounds in cockpit when canopy is open

* Added canopy/position-norm to flight recorder
* When opening the canopy, switch to external sounds
    - One value in the code (in Systems/canopy.xml) controls when it switches from internal to external sounds
    - You can modify this value if you want or replace it with a \<property\> element if you want to define the value in the -set.xml file
    - Avionics 400 Hz, nose wheel rumble, and high-alpha-airflow have been left untouched and do not depend on canopy state