* Move `api.v1.proto` schema into new crate `sc-network-sync`
* Move `sc_network::protocol::sync::state` module into `sc_network_sync::state`
* Move `sc_network::protocol::sync::blocks` module into `sc_network_sync::blocks` and some data structures from `sc_network::protocol::message` module into `sc_network_sync::message`
* Move some data structures from `sc_network::config` and `sc_network::request_responses` into new `sc-network-common` crate
* Move `sc_network::protocol::sync::warm` and `sc_network::warp_request_handler` modules into `sc_network_sync`
* Move `client/network/sync/src/lib.rs` to `client/network/sync/src/lib_old.rs` to preserve history of changes of the file in the next commit
* Move `client/network/src/protocol/sync.rs` on top of `client/network/sync/src/lib.rs` to preserve history of changes
* Move `sc_network::protocol::sync` to `sc_network_sync` with submodules, move message data structures around accordingly
* Move `sc_network::block_request_handler` to `sc_network_sync::block_request_handler`
* Move `sc_network::state_request_handler` to `sc_network_sync::state_request_handler`
* Add re-exports for compatibility reasons
* Apply suggestions from code review
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>