Turn storage items into parameters (#2883)

* balances: Turn storage items into parameters.

* contract: Turn storage items into parameters.

* council: Turn storage items into parameters.

* finality-tracker: Turn storage items into parameters.

* treasury: Turn storage items into parameters.

* democracy: Fix tests.

* example: Fix tests.

* executive: Fix tests.

* staking: Fix tests.

* Update runtime.

* Update template-node.

* Update runtime version.

* Fix executor tests.

* Fix node cli tests.

* Address grumbles.

* Add removed default values to docs.

* Make gas price a storage item.

* Set associated consts must be callable outside of build.

* Fix not enough gas to pay for transfer fee.

* Fix build.

* Emit metadata.

* Fix build.

* Add default values for all parameter types.

* Fix build.

* Fix build.

* Fix build.

* Fix build.