URI template support

[findleyr]

Now that the SDK is no longer in the golang.org/x/tools repo, we should update our resource template parsing to use https://github.com/yosida95/uritemplate, rather than the current quick-and-dirty implementation.

[samthanawalla]

• Replace mcp/resource.go:uriTemplateToRegexp with the uritemplate.Regexp() function.
• Update go.mod
• Update tests

[cryo-zd]

// Matches reports whether the receiver's uri template matches the uri.
func (sr *ServerResourceTemplate) Matches(uri string) bool {
	tmpl, err := uritemplate.New(sr.ResourceTemplate.URITemplate)
	if err != nil {
		return false
	}
	return tmpl.Regexp().MatchString(uri)
}

During testing, I came across an invalid URI template ("file:///{}/{a}/{b}") which doesn't conform to RFC 6570 due to the empty {} expression. I’ve updated the test cases to reflect this change and ensure everything works as expected.

Could you kindly review this implementation and let me know if it aligns with the expected behavior? Your feedback would be greatly appreciated!Thank you for your time and looking forward to hearing your thoughts.

[jba]

@cryo-zd Yes, empty braces violate the spec. Thanks for catching that.

Where did you make your edits?