Using SITL with Morse

[auturgy]

Fresh Morse install on Ubuntu 20.04 not working. This isn't an ArduPilot issue, but it does need to be noted until resolved. Issue raised on Morse here: morse-simulator/morse#822
Steps to reproduce (from /ardupilot dir):

sudo apt install morse-simulator
morse run libraries/SITL/examples/Morse/quadcopter.py

Full console dump is at shorturl.at/svJM6
but basically Blender quits due to uncaught exception,
AttributeError: 'Object' object has no attribute 'hide'.
Doesn't seem to be related to ArduPilot - same error occurs regardless if starting the default Morse vehicle.

``` returns 
...
* Your environment is correctly setup to run MORSE.

```morse create my_first_sim
   morse run my_first_sim 

returns same error (AttributeError: 'Object' object has no attribute 'hide'.) as running the ardupilot script

[peterbarker]

I'll also note that if you do hack that attribute "hide" problem (the fix is googleable) then a more intractable exception crops up next.

Workaround might be to install Blender 2.79 somehow using snap - theory only.

[auturgy]

Closed #3465