Add JSON-based setup option to authorization server conformance test

Background

In the future, conformance test for authorization server requires many options such as url, client_id, client_secret, redirect_uri.

Solution

Conformance test for authorization server provides the following setup options so that testers can choose their preferred setup option. The number is priority of the options. However, options unrelated to the authorization server, such as outputDir and specVersion, are not covered from these setup options.

1. command options
2. json file option
3. default value

For Example

In the following case, http://auth1.example.com, which is set in url option, will be used.

npx @modelcontextprotocol/conformance authorization --file autorization-server-settings.json --url http://auth1.example.com

In the following case, http://auth2.example.com, which is set in autorization-server-settings.json, will be used.

npx @modelcontextprotocol/conformance authorization --file autorization-server-settings.json

autorization-server-settings.json

{
  "url": "http://auth2.example.com"
}

In the following case, conformance test for authorization server occures error.

npx @modelcontextprotocol/conformance authorization

Start from the authorization conformance-test command and its existing command-option handling. Add the JSON setup option with command options taking precedence over JSON values and defaults, and preserve errors when required authorization-server settings are absent; verify the three example invocation cases.