Title: Support metadata input in Matching API

Description:
The Matching API currently doesn't support Metata Input. It would be valuable if Envoy could support it.

For instance, we prefer using Matcher over RBAC rules for authorization due to its flexibility. However, while RBAC allows specifying metadata as the principal, the matcher API currently lacks this capability, limiting use cases such as JWT claims as principals.

The supported Matching Inputs: https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/advanced/matching/matching_api#extension-category-envoy-matching-http-input

@arkodg