Refactor the balances module (#4649)

* Initially scoping out of the problem

* Remove need for exiry in balance locks.

* Remove expiry from locks.

* Remove supefluous balance test

* Amalgamate pieces of balance module

* Split out vesting

* Fix tests

* Fixes for vesting.

* Docs.

* Weight docs.

* Refactor things in terms of set_balances.

* Switch out ED to be free + reserved.

* Remove on_free_balance_zero and some docs.

* Build fixes

* Update frame/vesting/src/lib.rs

Co-Authored-By: Xiliang Chen <xlchen1291@gmail.com>

* Update frame/vesting/src/lib.rs

Co-Authored-By: Xiliang Chen <xlchen1291@gmail.com>

* Migration

* Remove superfluous code.

* Test fixes

* Fix some tests

* Fix repatriate reserve

* Fixes

* Add test for migration

* Final cleanups

* Fix

* Indentation.

* Undo unneeded referencing

* Bump runtime version

* Fixes

Co-authored-by: Xiliang Chen <xlchen1291@gmail.com>

substrate/bin/node-template/runtime/src/lib.rs

@@ -196,15 +196,12 @@ impl timestamp::Trait for Runtime {
 
 parameter_types! {
 	pub const ExistentialDeposit: u128 = 500;
-	pub const TransferFee: u128 = 0;
 	pub const CreationFee: u128 = 0;
 }
 
 impl balances::Trait for Runtime {
 	/// The type for recording an account's balance.
 	type Balance = Balance;
-	/// What to do if an account's free balance gets zeroed.
-	type OnFreeBalanceZero = ();
 	/// What to do if an account is fully reaped from the system.
 	type OnReapAccount = System;
 	/// What to do if a new account is created.
@@ -214,7 +211,6 @@ impl balances::Trait for Runtime {
 	type DustRemoval = ();
 	type TransferPayment = ();
 	type ExistentialDeposit = ExistentialDeposit;
-	type TransferFee = TransferFee;
 	type CreationFee = CreationFee;
 }