Support GoLang Http Filter in EnvoyExtensionPolicy

*Description*:

Can we already start with implementing [GoLang Http Filter](https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_filters/golang_filter)

Even though it is as of now not included in the core image of envoy proxy?
But there is some progress regarding movement and some really promising quotes from [here](https://github.com/envoyproxy/envoy/issues/31685) and [here](https://github.com/envoyproxy/envoy/issues/36026)
* "should be stable enough"
* "known bugs are fixed"
* "I think it's ready for production"
* "Go plugin API is stable enough"
* "let's make it happen in 2025"

The envoy:contrib version could be easily used by changing the image in the API [here](https://www.envoyproxy.io/docs/envoy/latest/start/sandboxes/golang-http). For sure that has to be highlighted in the documentation. And maybe part of the validation process.

Links:
* https://www.envoyproxy.io/docs/envoy/latest/start/sandboxes/golang-http
* https://github.com/envoyproxy/gateway/issues/2204
* https://github.com/envoyproxy/gateway/issues/2025