Fix raw:// URL parsing logic

[jl-martins]

Summary

Fixes #686

List of files changed and why

• crawl4ai/async_crawler_strategy.py - To fix the logic that converts raw URLs to raw HTML
• tests/20241401/test_async_crawler_strategy.py - To test the fix

How Has This Been Tested?

By implementing a parametrized test that calls AsyncPlaywrightCrawlerStrategy.crawl with a "raw:" and "raw://" URL and checks that the resulting HTML is correct.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added/updated unit tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[jl-martins]

Some tests are failing locally, but they were already failing before the fix, for reasons unrelated to this PR.

[RipFacuu]

good