Move block/state/warpc sync requests/responses to ChainSync (#12739)

* Move block/state/warpc sync requests/responses to `ChainSync`

* Apply suggestions from code review

Co-authored-by: Bastian Köcher <git@kchr.de>

* Apply review suggestions

* cargo-fmt + doc fix

* Fix tests

Co-authored-by: Bastian Köcher <git@kchr.de>

substrate/Cargo.lock

@@ -340,9 +340,9 @@ checksum = "e91831deabf0d6d7ec49552e489aed63b7456a7a3c46cff62adad428110b0af0"
 
 [[package]]
 name = "async-trait"
-version = "0.1.57"
+version = "0.1.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "76464446b8bc32758d7e88ee1a804d9914cd9b1cb264c029899680b0be29826f"
+checksum = "1e805d94e6b5001b651426cf4cd446b1ab5f319d27bab5c644f61de0a804360c"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -8321,6 +8321,7 @@ version = "0.10.0-dev"
 dependencies = [
  "array-bytes",
  "async-std",
+ "async-trait",
  "fork-tree",
  "futures",
  "libp2p",