runtime: Account nicknames (#3930)

* Add Nicknames module for accounts.

* Integrate into node.

* Fix build

* Update srml/nicks/src/lib.rs

Co-Authored-By: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

* Bump runtime

* Improve weight docs

* Docs.

* Apply suggestions from code review

Co-Authored-By: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/Cargo.lock

@@ -2525,6 +2525,7 @@ dependencies = [
  "srml-im-online 0.1.0",
  "srml-indices 2.0.0",
  "srml-membership 2.0.0",
+ "srml-nicks 2.0.0",
  "srml-offences 1.0.0",
  "srml-randomness-collective-flip 2.0.0",
  "srml-session 2.0.0",
@@ -4350,6 +4351,21 @@ dependencies = [
  "substrate-primitives 2.0.0",
 ]
 
+[[package]]
+name = "srml-nicks"
+version = "2.0.0"
+dependencies = [
+ "parity-scale-codec 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "serde 1.0.101 (registry+https://github.com/rust-lang/crates.io-index)",
+ "sr-io 2.0.0",
+ "sr-primitives 2.0.0",
+ "sr-std 2.0.0",
+ "srml-balances 2.0.0",
+ "srml-support 2.0.0",
+ "srml-system 2.0.0",
+ "substrate-primitives 2.0.0",
+]
+
 [[package]]
 name = "srml-offences"
 version = "1.0.0"