[FIX] Ensure qasync loop is set as running

[ales-erjavec]

Issue

Requesting help for a widget when using the latest released qasync v0.24.2 fails with an exception

Traceback (most recent call last):
  File "/Users/aleserjavec/workspace/orange-canvas/orangecanvas/application/canvasmain.py", line 2352, in run
    url = await query_coro
          ^^^^^^^^^^^^^^^^
  File "/Users/aleserjavec/workspace/orange-canvas/orangecanvas/help/manager.py", line 127, in search_async
    return await provider.search_async(desc, timeout=timeout)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/aleserjavec/workspace/orange-canvas/orangecanvas/help/provider.py", line 133, in search_async
    await asyncio.wait_for(reply_f, timeout)
  File "/Users/aleserjavec/.local/opt/python3.11/Python.framework/Versions/3.11/lib/python3.11/asyncio/tasks.py", line 439, in wait_for
    loop = events.get_running_loop()
           ^^^^^^^^^^^^^^^^^^^^^^^^^
RuntimeError: no running event loop

Changes

• Ensure qasync loop is set as the running loop.
• Some minor cleanup.

[codecov-commenter]

Codecov Report

All modified lines are covered by tests ✅

Comparison is base (02c70d2) 75.48% compared to head (622fb4e) 75.48%.
Report is 4 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #281   +/-   ##
=======================================
  Coverage   75.48%   75.48%           
=======================================
  Files          99       99           
  Lines       21031    21032    +1     
=======================================
+ Hits        15875    15876    +1     
  Misses       5156     5156           

Files	Coverage Δ
orangecanvas/utils/asyncutils.py	86.66% <100.00%> (+6.02%)	⬆️

... and 1 file with indirect coverage changes

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