[Feature] Envoy Gateway Monitoring

### Search before asking

- [X] I had searched in the [issues](https://github.com/apache/skywalking/issues?q=is%3Aissue) and found no similar feature requirement.

### Description

Envoy begins to release Envoy Gateway as a separate project, **Manages Envoy Proxy as a Standalone or Kubernetes-based Application Gateway**.

It also provided [`Prometheus + Grafana` Integration](https://gateway.envoyproxy.io/v0.6.0/user/grafana-integration/), and envoy has ALS and Metrics service as well.

We should evaluate how to integrate with the EG and provide default dashboard for it.

### Use case

_No response_

### Related issues

_No response_

### Are you willing to submit a pull request to implement this on your own?

- [ ] Yes I am willing to submit a pull request on my own!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct)