fix(async,csv,fmt): assign default value when undefined is passed

[petamoriken]

Related #5892 (comment)

When using spread syntax or Object.assign, if a property with undefined is passed, overrides it.

const options = { foo: undefined };

const spreaded = { foo: 1, ...options };
// => { foo: undefined }

const assigned = Object.assign({ foo: 1 }, options);
// => { foo: undefined }

This PR solves that problem by delaying the assignment of default values.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.31%. Comparing base (2d6c45e) to head (77984dc).
Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5893      +/-   ##
==========================================
- Coverage   96.33%   96.31%   -0.03%     
==========================================
  Files         483      483              
  Lines       39042    39035       -7     
  Branches     5712     5717       +5     
==========================================
- Hits        37613    37595      -18     
- Misses       1385     1396      +11     
  Partials       44       44              

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

[iuioiua]

LGTM. Thank you!