Add crawler for Hagezi blocklist and corresponding forward dns data

[romain-fontugne]

This pull request adds Hagezi DNS blocklists, as resolved and published by IHR. Maybe the PR is a bit premature as we are just starting collecting this dataset but anyways it is ready.

Hagezi DNS Blocklists Integration:

• Added a new crawler in iyp/crawlers/hagezi/blocklists_forward_dns.py to fetch, parse, and import Hagezi DNS blocklists and their DNS resolution results.
• Added corresponding readme iyp/crawlers/hagezi/README.md
• Updated documentation/data-sources.md to include Hagezi as a new data source with details and links.
• Added an entry for the new crawler in config.json.example so it can be enabled and configured.
• Updated ACKNOWLEDGMENTS.md

How Has This Been Tested?

Locally tested on an old snapshot of IYP.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[m-appel]

Merged in ffead13.