composite: add implementation for filter_chain (#42724)

## Description

This PR adds the implementation for `filter_chain` in the Composite
Filter. The API was added as part of
[this](envoyproxy/envoy#40885) PR.

This would allow multiple HTTP filters to be delegated to as a single
action, with filters executing in order for decoding and reverse order
for encoding.

---

**Commit Message:** composite: add implementation for filter_chain
**Additional Description:** Adds the implementation for `filter_chain`
in the Composite Filter.
**Risk Level:** Low
**Testing:** Added Unit + Integration Tests
**Docs Changes:** Added
**Release Notes:** Added

Signed-off-by: Rohit Agrawal <[email protected]>

Mirrored from https://github.com/envoyproxy/envoy @ 77b78698f753d78b39863002149a76133d162d86

Author: update-envoy[bot]

envoy/extensions/filters/http/composite/v3/composite.proto

@@ -74,7 +74,7 @@ message ExecuteFilterAction {
       [(udpa.annotations.field_migrate).oneof_promotion = "config_type"];
 
   // An inlined list of filter configurations. The specified filters will be executed in order.
-  // [#not-implemented-hide:]
+  // If this field is set, ``typed_config`` and ``dynamic_config`` are ignored.
   FilterChainConfiguration filter_chain = 4;
 
   // Probability of the action execution. If not specified, this is 100%.