Extract peers grid topology related code to a separate unit (#5365)

* Initial attempt to extract grid topology related code

* Use shared code in the approval distribution subsystem

* Fix spellcheck issues

* Moe Aggression stuff back to the approval-distribution subsystem

* Cargo fmt

polkadot/node/network/protocol/src/lib.rs

@@ -40,6 +40,8 @@ pub mod request_response;
 
 /// Accessing authority discovery service
 pub mod authority_discovery;
+/// Grid topology support module
+pub mod grid_topology;
 
 /// A version of the protocol.
 pub type ProtocolVersion = u32;