[DOP-8664] - Allow modes "ignore" and "error" in MongoDB.WriteOptions

[maxim-lixakov]

Change Summary

• add ignore and error modes (if_exists=...) to MongoDB.WriteOptions
• add unit and integration tests
• updated documentation

Related issue number

Checklist

• Commit message and PR title is comprehensive
• Keep the change as small as possible
• Unit and integration tests for the changes exist
• Tests pass on CI and coverage does not decrease
• Documentation reflects the changes where applicable
• docs/changelog/next_release/<pull request or issue id>.<change type>.rst file added describing change
  (see CONTRIBUTING.rst for details.)
• My PR is ready to review.

[codecov]

Codecov Report

Merging #145 (e205d8e) into develop (0adf055) will increase coverage by 0.03%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop     #145      +/-   ##
===========================================
+ Coverage    94.24%   94.28%   +0.03%     
===========================================
  Files          207      207              
  Lines         7703     7720      +17     
  Branches      1449     1453       +4     
===========================================
+ Hits          7260     7279      +19     
+ Misses         322      321       -1     
+ Partials       121      120       -1     

Files Changed	Coverage Δ
...etl/connection/db_connection/mongodb/connection.py	93.75% <100.00%> (+0.52%)	⬆️
onetl/connection/db_connection/mongodb/options.py	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes