Update to libp2p-0.23. (#6870)

* Update to libp2p-0.23.

Thereby incorporate bandwidth measurement along the
lines previously done by libp2p itself.

* Tweak dependencies for wasm32 compilation.

For wasm32 we need to enable unstable features to
make `task::Builder::local` available.

* Simplify dependencies.

* Simplify.

Leave the calculation of bytes sent/received per second
to the outer layers of the code, subject to their own
individual update intervals.

* Cleanup

* Re-add lost dev dependency.

* Avoid division by zero.

* Remove redundant metric.

* Enable sending of noise legacy handshakes.

* Add comment about monotonic gauge.

* CI

substrate/client/network/Cargo.toml

@@ -26,7 +26,7 @@ erased-serde = "0.3.9"
 fnv = "1.0.6"
 fork-tree = { version = "2.0.0-rc5", path = "../../utils/fork-tree" }
 futures = "0.3.4"
-futures-timer = "3.0.1"
+futures-timer = "3.0.2"
 futures_codec = "0.4.0"
 hex = "0.4.0"
 ip_network = "0.3.4"
@@ -61,7 +61,7 @@ wasm-timer = "0.2"
 zeroize = "1.0.0"
 
 [dependencies.libp2p]
-version = "0.22.0"
+version = "0.23.0"
 default-features = false
 features = ["identify", "kad", "mdns", "mplex", "noise", "ping", "tcp-async-std", "websocket", "yamux"]
 
@@ -69,7 +69,7 @@ features = ["identify", "kad", "mdns", "mplex", "noise", "ping", "tcp-async-std"
 async-std = "1.6.2"
 assert_matches = "1.3"
 env_logger = "0.7.0"
-libp2p = { version = "0.22.0", default-features = false, features = ["secio"] }
+libp2p = { version = "0.23.0", default-features = false, features = ["secio"] }
 quickcheck = "0.9.0"
 rand = "0.7.2"
 sp-keyring = { version = "2.0.0-rc5", path = "../../primitives/keyring" }