add generated weight info for pallet-collective (#6789)

* add benchmark for disapprove_proposal

* use generated WeightInfo for pallet-collective weights

* order collective benchmark params alphabetically to get a consistent ordering

* address review comments

* remove default impl of WeightInfo for ()

* remove comments about weight changes

* add default weights

* Apply suggestions from code review

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

* whitelist voter account in benchmark

* update weights

* MaxMembers configurable

* remove base weight comment

* add weight to technical collective

* another DB whitelist optimization

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