Commit Message: adding filter state matching input
Additional Description: Adding a matching input of type 'FilterStateInput', that retrieves a specific filter state object by a given key and uses the serialized value as a matching candidate.
Risk Level: low
Testing: unit and integration tests
Docs Changes: matcher_api
Release Notes: none
Platform Specific Features: none
Mirrored from https://github.com/envoyproxy/envoy @ f52d559e0479824b9c964e4c028fa373bcb9b767
Introduce data inputs for connection matching as part of #18871
Signed-off-by: Kuat Yessenov <kuat@google.com>
Mirrored from https://github.com/envoyproxy/envoy @ a1181348a4f6df6011843a141814e28840d23eb5