Replace DNS0.eu with DNS4EU service - Fixes #3154

[Rutuja123-dos]

Description

This PR replaces the deprecated DNS0.eu service with the new DNS4EU service.
This includes updates to both the DNS Resolver and the Malicious Domain Detector.
Fixes #3154

• 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 not work as expected).

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[mlodic]

read through the PR template properly please and compile the items, the PR is not against develop