Redesign Democracy pallet (#5294)

* Repot a bit of democracy code

* Basic logic is drafted

* Lazy democracy builds.

* Add non-locked split-voting and instant-scheduling.

* Introduce delegation that works.

* Builds again.

* Indentation

* Building.

* Docs and migration

* Fix half of the tests

* Fix up & repot tests

* Fix runtime build

* Update docs

* Docs

* Nits.

* Turnout counts full capital

* Delegations could towards capital

* proxy delegation & proxy unvoting

* Fix

* Tests for split-voting

* Add missing file

* Persistent locking.