migration(democracy): unreserve deposits and clear locks (#14226)

* unlock and unreserve all migration

* log total amount to unlock

* clippy

* clippy

* simplify balance types

* add tests

* fix comment

* fix std features

* remove redundant dev-dep

* address comments

* remove redundant std

* estimate weights

* fix comments

* fix tests

* clippy

* track democracy bugged deposits

* improve pre_migration logs

* oliver comments from tips pr

* run pre and post hooks in tests

* flexible dbweight type

* Update frame/democracy/src/migrations/unlock_and_unreserve_all_funds.rs

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Update frame/democracy/src/migrations/unlock_and_unreserve_all_funds.rs

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

* Update frame/democracy/src/migrations/unlock_and_unreserve_all_funds.rs

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* docs

* Update frame/democracy/src/lib.rs

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Update frame/democracy/src/migrations/unlock_and_unreserve_all_funds.rs

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* add log target

* fix visibility

* lint

* use log target

---------

Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>