[picazor] add extractor

[petercunha]

Description

This PR adds a new extractor for Picazor.

Features

• Supports downloading user profiles: https://picazor.com/en/<username>
• Extracts high-quality images.
• Handles pagination automatically.
• Bypasses 403 Forbidden protection using specific Referer headers and browser emulation.

Implementation Details

• Extractor: gallery_dl/extractor/picazor.py
  • Uses Message.Directory to initialize path formatting.
  • Implements nameext_from_url to correctly handle file extensions.
  • Adds path metadata field for filename formatting.
  • Sets firefox browser emulation to match valid user agents.
• Tests: test/results/picazor.py
  • Validates URL matching, metadata extraction (user, path), and regression tests.

Type of Change

• New feature (non-breaking change which adds functionality)

Verification

• Ran automated tests: python test/test_results.py picazor -> Passed
• Manual verification (dry-run): python -m gallery_dl --no-download https://picazor.com/en/kailey-mae -> Successfully listed files

Related Files

• gallery_dl/extractor/picazor.py
• test/results/picazor.py
• gallery_dl/extractor/__init__.py
• docs/supportedsites.md