* Init vesting module.

* Impl add vesting schedule.

* Renaming dependencies.

* Renaming vesting module event.

* Checked arithmatic.

* Adding new vesting schedule merges with outstanding locked balance and until.

* Make VestingSchedule fields public.

* Claim vesting.

* Update locked_amount calculation.

* Unique saturated into.

* Unit test of claim call.

* Add update_vesting_schedules.

* update_vesting_shedules unit tests.

* Ensure lockable.

* Minor fixes.

* Remove todo comment.

* Merge fixme comments.