Update clap to the latest version (#11017)

* Update clap to the latest version

Besides that it also removes some `structopt` leftovers from some docs.

* Fix compile errors

* More fixes

substrate/bin/utils/chain-spec-builder/Cargo.toml

@@ -15,7 +15,7 @@ targets = ["x86_64-unknown-linux-gnu"]
 
 [dependencies]
 ansi_term = "0.12.1"
-clap = { version = "3.0", features = ["derive"] }
+clap = { version = "3.1.6", features = ["derive"] }
 rand = "0.8"
 
 sc-keystore = { version = "4.0.0-dev", path = "../../../client/keystore" }

substrate/bin/utils/subkey/Cargo.toml

@@ -17,5 +17,5 @@ path = "src/main.rs"
 name = "subkey"
 
 [dependencies]
-clap = { version = "3.0", features = ["derive"] }
+clap = { version = "3.1.6", features = ["derive"] }
 sc-cli = { version = "0.10.0-dev", path = "../../../client/cli" }