[DOP-6705] Add CSV file format

[dolfinus]

Change Summary

• Added CSV file format class and related documentation & unit tests
• Small fix of typing of GenericOptions.parse method

If was previously planned to implement nested classes:

• CSV.Reading(delimiter=',', inferSchema=True)
• CSV.Writing(delimiter=',', compression='gzip')

But all implementations I've tried were messy or quite tricky to make working as expected.

So instead I've merged all options to just one class. We don't do anything with input options, they are just passed to Spark as-is, and there is no actual reason to make them separated to 2 classes.

Also I've added several default options just to class instead of known_options to improve developer experience - IDE should suggest attribute names, default values will be printed to logs, etc.

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 #69 (c64c671) into develop (f4affb6) will decrease coverage by 0.03%.
The diff coverage is 90.38%.

@@             Coverage Diff             @@
##           develop      #69      +/-   ##
===========================================
- Coverage    93.16%   93.13%   -0.03%     
===========================================
  Files          129      132       +3     
  Lines         6146     6192      +46     
  Branches      1149     1156       +7     
===========================================
+ Hits          5726     5767      +41     
- Misses         322      327       +5     
  Partials        98       98              

Impacted Files	Coverage Δ
onetl/base/base_file_format.py	100.00% <ø> (ø)
onetl/file/format/file_format.py	80.00% <80.00%> (ø)
onetl/file/format/csv.py	95.83% <95.83%> (ø)
onetl/connection/db_connection/mongodb.py	94.09% <100.00%> (ø)
onetl/file/format/__init__.py	100.00% <100.00%> (ø)
onetl/impl/generic_options.py	100.00% <100.00%> (ø)