pallet-session: Migrate the historical part to the new pallet macro (#9878)

* Migrate session-historical to the new pallet macro

Signed-off-by: koushiro <koushiro.cqx@gmail.com>

* pallet-session: Migrate the historical part to the new pallet macro

Signed-off-by: koushiro <koushiro.cqx@gmail.com>

* Fix staking test runtime

Signed-off-by: koushiro <koushiro.cqx@gmail.com>

* Update frame/session/src/historical/mod.rs

* Update frame/session/src/historical/mod.rs

* update migration doc

Signed-off-by: koushiro <koushiro.cqx@gmail.com>

* use hardcoded prefix for migration v1

Signed-off-by: koushiro <koushiro.cqx@gmail.com>

* cargo +nightly-2021-11-08 fmt

Signed-off-by: koushiro <koushiro.cqx@gmail.com>

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>