Support resource param for Client Credentials token requests

📑 I have found these related issues/pull requests I have been unable to find any issues or pull requests that directly relate to the addition of the (optional) resource parameter to requests to the AS token endpoint. 🔖 Feature description Uptime Kuma supports the use of OAuth2: Client Credentials as a means for accessing resources behind an oauth2 enabled proxy. Part of the flow for receiving a bearer token is requesting a token from the authorization server (AS). That request usually looks something like this: Which returns a bearer token that can be used to access a protected resource. In more advanced requests, an client can specifically indicate the resource (or resources) they intend to access which looks like this: The authorization server can use this indicator to apply policies for the resource, like determining the type and content of tokens to be issued. ✔️ Solution Support adding an "OAuth2 Resource" parameter to Client Credential requests that allows mu…