[Server] Fix: extract and pass URI template variables to resource handlers

[CodeWithKyrian]

This PR fixes resource template functionality by properly extracting URI template variables and passing them to resource handler methods.

Motivation & Context

Resource templates have never worked correctly since their implementation. While the URI matching logic was functional, the extracted variables from URI patterns (like userId from user://{userId}/profile) were not being passed to handler methods, making it impossible for handlers to receive the expected parameters and rendering resource templates completely non-functional.

What's Changed

• Added method to ResourceTemplateReference to extract variables from URIs using regex matches
• Modified ReadResourceHandler to detect template references and merge extracted variables into handler arguments

Breaking Changes

None

[chr-hertel]

Looooks goood 🙌 Thanks @CodeWithKyrian!