Add support for tuples in `OnNewAccount` hook (#2765)

* Add support for tuples in `OnNewAccount` hook

* Bump impl version

* Use `for_each_tuple` with `OnNewAccount` hook

* Update `OnFreeBalanceZero` to also use `for_each_tuple`

* Fix spelling/typo

* Bump spec again

* Update srml/support/src/traits.rs

Co-Authored-By: Bastian Köcher <[email protected]>

* Update srml/system/src/lib.rs

Co-Authored-By: Bastian Köcher <[email protected]>