Add weight annotations to Timestamp, Sudo, Democracy, Treasury, et al. (#2694)

* Add some initial weighting notes

* Add Democracy and Sudo

* Add flags, fix formatting

* Add comments on finality-tracker

* Add a few mode modules.

* Update srml/democracy/src/lib.rs

Co-Authored-By: joe petrowski <[email protected]>

* Update srml/democracy/src/lib.rs

Co-Authored-By: joe petrowski <[email protected]>

* Update srml/system/src/lib.rs

Co-Authored-By: joe petrowski <[email protected]>

* Update srml/system/src/lib.rs

Co-Authored-By: joe petrowski <[email protected]>

* Update srml/system/src/lib.rs

Co-Authored-By: joe petrowski <[email protected]>

* Update srml/system/src/lib.rs

Co-Authored-By: joe petrowski <[email protected]>

* Update srml/treasury/src/lib.rs

Co-Authored-By: joe petrowski <[email protected]>

* Update and merge changes

* Update srml/system/src/lib.rs

Co-Authored-By: joe petrowski <[email protected]>

* Remove unneeded comment

* Remove comment line

* Fix comment

* Fix formatting overall

* Apply suggestions from code review

Co-Authored-By: joe petrowski <[email protected]>

* Apply suggestions from code review

Co-Authored-By: joe petrowski <[email protected]>

* Clean up and polish

* Update srml/indices/src/lib.rs

* Update srml/staking/src/lib.rs

Co-Authored-By: joe petrowski <[email protected]>

* Final nits.