Track in stats which fields from Zyte API automatic extraction are not overridden

[Gallaecio]

Requested by @VMRuiz.

It adds stats that indicate which fields from dependency injection come from Zyte API automatic extraction.

When directly requesting an item type, e.g. Product, the entire list of fields is tracked in stats:

 'scrapy-zyte-api/auto_fields/zyte_common_items.items.product.Product': 'additionalProperties '
                                                                        'aggregateRating '
                                                                        'availability '
                                                                        'brand '
                                                                        'breadcrumbs '
                                                                        'canonicalUrl '
                                                                        'color '
                                                                        'currency '
                                                                        'currencyRaw '
                                                                        'description '
                                                                        'descriptionHtml '
                                                                        'features '
                                                                        'gtin '
                                                                        'images '
                                                                        'mainImage '
                                                                        'metadata '
                                                                        'mpn '
                                                                        'name '
                                                                        'price '
                                                                        'productId '
                                                                        'regularPrice '
                                                                        'size '
                                                                        'sku '
                                                                        'style '
                                                                        'url '
                                                                        'variants',

When using a page object that overrides some fields, the stat reflects the corresponding page object, and the override fields are removed, e.g. aggregateRating here:

 'scrapy-zyte-api/auto_fields/zyte_spider_templates_project.pages.books_toscrape_com.BooksToScrapeComProductPage': 'additionalProperties '
                                                                                                                   'availability '
                                                                                                                   'brand '
                                                                                                                   'breadcrumbs '
                                                                                                                   'canonicalUrl '
                                                                                                                   'color '
                                                                                                                   'currency '
                                                                                                                   'currencyRaw '
                                                                                                                   'description '
                                                                                                                   'descriptionHtml '
                                                                                                                   'features '
                                                                                                                   'gtin '
                                                                                                                   'images '
                                                                                                                   'mainImage '
                                                                                                                   'metadata '
                                                                                                                   'mpn '
                                                                                                                   'name '
                                                                                                                   'price '
                                                                                                                   'productId '
                                                                                                                   'regularPrice '
                                                                                                                   'size '
                                                                                                                   'sku '
                                                                                                                   'style '
                                                                                                                   'url '
                                                                                                                   'variants',

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.67%. Comparing base (cd0aead) to head (c64d781).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #202      +/-   ##
==========================================
+ Coverage   97.62%   97.67%   +0.04%     
==========================================
  Files          14       14              
  Lines        1517     1546      +29     
  Branches      320      327       +7     
==========================================
+ Hits         1481     1510      +29     
  Misses         15       15              
  Partials       21       21              

Files	Coverage Δ
scrapy_zyte_api/providers.py	94.15% <100.00%> (+1.19%)	⬆️

[Gallaecio]

@asadurski All good on your end? Shall we merge and release?

[asadurski]

@asadurski All good on your end? Shall we merge and release?

Yes, this has all the things I need and looks great!