Network sync refactoring (part 4) (#11412)

* Remove direct dependency of `sc-network` on `sc-network-light`

* Move `WarpSyncProvider` trait and surrounding data structures into `sc-network-common`

* Move `WarpSyncProvider` trait and surrounding data structures into `sc-network-common`

* Create `sync` module in `sc-network-common`, create `ChainSync` trait there (not used yet), move a bunch of associated data structures from `sc-network-sync`

* Switch from concrete implementation to `ChainSync` trait from `sc-network-common`

* Introduce `OpaqueStateRequest`/`OpaqueStateResponse` to remove generics from `StateSync` trait

* Introduce `OpaqueBlockRequest`/`OpaqueBlockResponse`, make `scheme` module of `sc-network-sync` private

* Surface `sc-network-sync` into `sc-service` and make `sc-network` not depend on it anymore

* Remove now unnecessary dependency from `sc-network`

* Replace crate links with just text since dependencies are gone now

* Remove `warp_sync` re-export from `sc-network-common`

* Update copyright in network-related files

* Address review comments about documentation

* Apply review suggestion

* Rename `extra_requests` module to `metrics`

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

substrate/Cargo.lock

@@ -8429,6 +8429,7 @@ dependencies = [
  "sc-consensus",
  "sc-keystore",
  "sc-network",
+ "sc-network-common",
  "sc-network-gossip",
  "sc-network-test",
  "sc-telemetry",
@@ -8553,7 +8554,6 @@ dependencies = [
  "sp-blockchain",
  "sp-consensus",
  "sp-core",
- "sp-finality-grandpa",
  "sp-runtime",
  "sp-test-primitives",
  "sp-tracing",
@@ -8571,12 +8571,17 @@ dependencies = [
 name = "sc-network-common"
 version = "0.10.0-dev"
 dependencies = [
+ "bitflags",
  "futures",
  "libp2p",
  "parity-scale-codec",
  "prost-build",
+ "sc-consensus",
  "sc-peerset",
  "smallvec",
+ "sp-consensus",
+ "sp-finality-grandpa",
+ "sp-runtime",
 ]
 
 [[package]]
@@ -8621,8 +8626,6 @@ dependencies = [
 name = "sc-network-sync"
 version = "0.10.0-dev"
 dependencies = [
- "bitflags",
- "either",
  "fork-tree",
  "futures",
  "libp2p",
@@ -8667,6 +8670,8 @@ dependencies = [
  "sc-consensus",
  "sc-network",
  "sc-network-common",
+ "sc-network-light",
+ "sc-network-sync",
  "sc-service",
  "sp-blockchain",
  "sp-consensus",
@@ -8849,6 +8854,8 @@ dependencies = [
  "sc-keystore",
  "sc-network",
  "sc-network-common",
+ "sc-network-light",
+ "sc-network-sync",
  "sc-offchain",
  "sc-rpc",
  "sc-rpc-server",