Function build_authorization_url 

pub fn build_authorization_url(
    auth_endpoint: &str,
    client_id: &str,
    redirect_uri: &str,
    state: &str,
    code_challenge: &str,
    code_challenge_method: &str,
    resource: &str,
    scopes: &[String],
) -> McpResult<String>

Build authorization URL for OAuth flow