Refactor async notifiers implementation

[asvetlov]

The PR doesn't affect existing functionality but simplifies the code.

[codspeed-hq]

CodSpeed Performance Report

Merging #717 will not alter performance

_{Comparing refactor (c11d809) with master (a85cc40)}

Summary

✅ 4 untouched benchmarks

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 94.55%. Comparing base (a85cc40) to head (c11d809).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #717      +/-   ##
==========================================
+ Coverage   94.18%   94.55%   +0.37%     
==========================================
  Files           5        5              
  Lines        1495     1470      -25     
  Branches      135      129       -6     
==========================================
- Hits         1408     1390      -18     
+ Misses         54       53       -1     
+ Partials       33       27       -6     

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[x42005e1f]

There is if self._loop is not None on line 128. Maybe it should be deleted?

[asvetlov]

There is if self._loop is not None on line 128. Maybe it should be deleted?

Done