[Envoyproxy]: Enhance EnvoyProxy module dashboards in particular a map dashboard

### Integration Name

Envoyproxy [envoyproxy]

### Dataset Name

_No response_

### Integration Version

1.10.0

### Agent Version

9.1.3

### OS Version and Architecture

Linux

### User Goal

We’ve configured Filebeat to collect Envoy proxy / Envoy Gateway logs using the envoyproxy module. While ingestion works well, the out-of-the-box dashboards feel dated and lack key traffic visibility that exists in other modules.

In particular, the Envoy dashboards do not include a geo / traffic map showing where requests originate from (e.g. based on client IP), which is available in modules such as nginx and traefik.

A modernised Envoy dashboard set with:
• Source traffic geo map
• Clear request flow and ingress visibility
• Better parity with nginx / traefik dashboards

would significantly improve observability for users running Envoy or Envoy Gateway as their primary ingress.

Is there a roadmap to refresh the Envoy dashboards?
### Existing Features

outdated dashboards

### What did you see?

dashboard - [Filebeat Envoyproxy] Overview

### Anything else?

_No response_

Start by reviewing the “Filebeat Envoyproxy” Overview dashboard and comparing it with the nginx and traefik dashboards referenced in the issue. Done should mean a modernized Envoy dashboard set with a source-traffic geo map, clearer request-flow and ingress visibility, and better parity with those modules.

Written by the indexing model from the issue text.