feat(async search): add export async search docs method

[forshev]

Description

Add a new method to export documents found by async search

Fixes #472

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 70.51%. Comparing base (4ad8f17) to head (2d068cb).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #473      +/-   ##
==========================================
+ Coverage   70.44%   70.51%   +0.06%     
==========================================
  Files         232      232              
  Lines       18371    18407      +36     
==========================================
+ Hits        12942    12979      +37     
+ Misses       4453     4451       -2     
- Partials      976      977       +1     

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