Aggregate subsets (#3493)

## Issue Addressed

Resolves #3238 

## Proposed Changes

Please list or describe the changes introduced by this PR.

## Additional Info

Please provide any additional information. For example, future considerations
or information useful for reviewers.

Cargo.lock

@@ -661,6 +661,7 @@ dependencies = [
  "tokio",
  "tokio-stream",
  "tree_hash",
+ "tree_hash_derive",
  "types",
  "unused_port",
 ]
@@ -7849,9 +7850,9 @@ dependencies = [
 
 [[package]]
 name = "ssz_types"
-version = "0.5.2"
+version = "0.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8052a1004e979c0be24b9e55940195553103cc57d0b34f7e2c4e32793325e402"
+checksum = "e43767964a80b2fdeda7a79a57a2b6cbca966688d5b81da8fe91140a94f552a1"
 dependencies = [
  "arbitrary",
  "derivative",