Fix pallet bags list and doc (#10231)

* fix bags list

* improve doc

* doc

* inner doc

* fix test

* Update docs in frame/election-provider-support/src/lib.rs

* fix staking impl

* prepend unsafe to clear and regenerate

* fix test

Co-authored-by: Keith Yeung <[email protected]>
Co-authored-by: Shawn Tabrizi <[email protected]>