Port PR from PBS-Go: HTTP Fetcher: Implement RFC 3986 compatibility as optional

[cross-repo-issue-creation]

A PR was merged over on PBS-Go

• HTTP Fetcher: Implement RFC 3986 compatibility as optional prebid-server#4272
• timestamp: 2025-06-25T20:37:19Z

[Net-burst]

Let's do the same thing in Java with the RFC-compliant way being set to false by default and flip it to true by default in the next major PBS release (4.0).