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/frame/elections/src/lib.rs

@@ -26,7 +26,7 @@
 use sp_std::prelude::*;
 use sp_runtime::{
 	RuntimeDebug, DispatchResult, print,
-	traits::{Zero, One, StaticLookup, Bounded, Saturating},
+	traits::{Zero, One, StaticLookup, Saturating},
 };
 use frame_support::{
 	decl_storage, decl_event, ensure, decl_module, decl_error,
@@ -894,7 +894,6 @@ impl<T: Trait> Module<T> {
 			MODULE_ID,
 			&who,
 			locked_balance,
-			T::BlockNumber::max_value(),
 			WithdrawReasons::all(),
 		);