Fix creating multiple MIDI interfaces

[lukaszsmolinski]

The absence of await_return=True in the ensure_main_thread results in it returning a Future, which appears to be the cause of the issue.

I also found a way to convert the midi_callback into a method.

[codecov]

Codecov Report

Attention: Patch coverage is 53.33333% with 7 lines in your changes are missing coverage. Please review.

Project coverage is 48.28%. Comparing base (4254c44) to head (a4daf35).
Report is 2 commits behind head on main.

Files	Patch %	Lines
..._app_controller/controller/connected_controller.py	36.36%	7 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #27      +/-   ##
==========================================
- Coverage   48.51%   48.28%   -0.24%     
==========================================
  Files          11       12       +1     
  Lines         606      611       +5     
==========================================
+ Hits          294      295       +1     
- Misses        312      316       +4     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[Jokilos]

Nice!