Fix csviter call, add parse_rows test

[Laerte]

Closes #5391

[codecov]

Codecov Report

Merging #5394 (775107b) into master (b282a7a) will decrease coverage by 4.24%.
The diff coverage is 100.00%.

❗ Current head 775107b differs from pull request most recent head db83e49. Consider uploading reports for the commit db83e49 to get more accurate results

@@            Coverage Diff             @@
##           master    #5394      +/-   ##
==========================================
- Coverage   88.54%   84.30%   -4.25%     
==========================================
  Files         163      163              
  Lines       10627    10627              
  Branches     1809     1807       -2     
==========================================
- Hits         9410     8959     -451     
- Misses        941     1406     +465     
+ Partials      276      262      -14     

Impacted Files	Coverage Δ
scrapy/spiders/feed.py	73.84% <100.00%> (+7.69%)	⬆️
scrapy/utils/asyncgen.py	33.33% <0.00%> (-66.67%)	⬇️
scrapy/core/http2/stream.py	27.01% <0.00%> (-64.37%)	⬇️
scrapy/pipelines/images.py	27.82% <0.00%> (-62.61%)	⬇️
scrapy/core/http2/agent.py	36.14% <0.00%> (-60.25%)	⬇️
scrapy/core/downloader/handlers/http2.py	43.42% <0.00%> (-56.58%)	⬇️
scrapy/core/http2/protocol.py	34.17% <0.00%> (-49.25%)	⬇️
scrapy/robotstxt.py	75.30% <0.00%> (-22.23%)	⬇️
scrapy/utils/test.py	43.75% <0.00%> (-17.19%)	⬇️
scrapy/utils/ssl.py	53.65% <0.00%> (-17.08%)	⬇️
... and 10 more

[wRAR]

Can you please look at the flake8 output?

[Laerte]

@wRAR Done.

[Gallaecio]

Closing and reopening to trigger CI jobs rebased on top of #5401.