Implement Network Bridge (#1280)

* network bridge skeleton

* move some primitives around and add debug impls

* protocol registration glue & abstract network interface

* add send_msgs to subsystemctx

* select logic

* transform different events into actions and handle

* implement remaining network bridge state machine

* start test skeleton

* make network methods asynchronous

* extract subsystem out to subsystem crate

* port over overseer to subsystem context trait

* fix minimal example

* fix overseer doc test

* update network-bridge crate

* write a subsystem test-helpers crate

* write a network test helper for network-bridge

* set up (broken) view test

* Revamp network to be more async-friendly and not require Sync

* fix spacing

* fix test compilation

* insert side-channel for actions

* Add some more message types to AllMessages

* introduce a test harness

* add some tests

* ensure service compiles and passes tests

* fix typo

* fix service-new compilation

* Subsystem test helpers send messages synchronously

* remove smelly action inspector

* remove superfluous let binding

* fix warnings

* Update node/network/bridge/src/lib.rs

Co-authored-by: Peter Goodspeed-Niklaus <coriolinus@users.noreply.github.com>

* fix compilation

Co-authored-by: Peter Goodspeed-Niklaus <coriolinus@users.noreply.github.com>

polkadot/Cargo.lock

@@ -256,6 +256,17 @@ dependencies = [
  "webpki-roots 0.19.0",
 ]
 
+[[package]]
+name = "async-trait"
+version = "0.1.36"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a265e3abeffdce30b2e26b7a11b222fe37c6067404001b434101457d0385eb92"
+dependencies = [
+ "proc-macro2 1.0.18",
+ "quote 1.0.7",
+ "syn 1.0.31",
+]
+
 [[package]]
 name = "atty"
 version = "0.2.14"
@@ -4348,6 +4359,25 @@ dependencies = [
  "wasm-timer",
 ]
 
+[[package]]
+name = "polkadot-network-bridge"
+version = "0.1.0"
+dependencies = [
+ "assert_matches",
+ "futures 0.3.5",
+ "futures-timer 3.0.2",
+ "log 0.4.8",
+ "parity-scale-codec",
+ "parking_lot 0.10.2",
+ "polkadot-node-primitives",
+ "polkadot-node-subsystem",
+ "polkadot-primitives",
+ "polkadot-subsystem-test-helpers",
+ "sc-network",
+ "sp-runtime",
+ "streamunordered",
+]
+
 [[package]]
 name = "polkadot-network-test"
 version = "0.8.13"
@@ -4370,9 +4400,21 @@ dependencies = [
 ]
 
 [[package]]
-name = "polkadot-node-messages"
+name = "polkadot-node-primitives"
 version = "0.1.0"
 dependencies = [
+ "async-trait",
+ "parity-scale-codec",
+ "polkadot-primitives",
+ "polkadot-statement-table",
+ "sp-runtime",
+]
+
+[[package]]
+name = "polkadot-node-subsystem"
+version = "0.1.0"
+dependencies = [
+ "async-trait",
  "futures 0.3.5",
  "polkadot-node-primitives",
  "polkadot-primitives",
@@ -4380,26 +4422,17 @@ dependencies = [
  "sc-network",
 ]
 
-[[package]]
-name = "polkadot-node-primitives"
-version = "0.1.0"
-dependencies = [
- "parity-scale-codec",
- "polkadot-primitives",
- "polkadot-statement-table",
- "sp-runtime",
-]
-
 [[package]]
 name = "polkadot-overseer"
 version = "0.1.0"
 dependencies = [
+ "async-trait",
  "femme",
  "futures 0.3.5",
  "futures-timer 3.0.2",
  "kv-log-macro",
  "log 0.4.8",
- "polkadot-node-messages",
+ "polkadot-node-subsystem",
  "polkadot-primitives",
  "sc-client-api",
  "streamunordered",
@@ -4711,6 +4744,7 @@ dependencies = [
  "parity-scale-codec",
  "parking_lot 0.9.0",
  "polkadot-network",
+ "polkadot-node-subsystem",
  "polkadot-overseer",
  "polkadot-primitives",
  "polkadot-rpc",
@@ -4760,6 +4794,16 @@ dependencies = [
  "sp-core",
 ]
 
+[[package]]
+name = "polkadot-subsystem-test-helpers"
+version = "0.1.0"
+dependencies = [
+ "async-trait",
+ "futures 0.3.5",
+ "parking_lot 0.10.2",
+ "polkadot-node-subsystem",
+]
+
 [[package]]
 name = "polkadot-test-runtime"
 version = "0.8.13"