Benchmarks for elections-phragmen pallet (#5845)

* Fist benchmark barely working

* Debug checkpoint

* add rest of benchmarks

* Add to runtime

* Fix build

* Update frame/elections-phragmen/src/benchmarking.rs

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

* Update frame/elections-phragmen/src/benchmarking.rs

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

* major imp

* Make them run on release

* Help finish phragmen benchmarks (#5886)

* update caller, account, and member/runner-up creation

* remove stuff

* ocd

* make it work with real run

* relax the numbers a bit

* New and improved version

* Make elections-phragmen weighable and secure. (#5949)

* Make elections-phragmen weighable.

* Update frame/elections-phragmen/src/lib.rs

Co-authored-by: Alexander Popiak <alexander.popiak@parity.io>

* Update frame/elections-phragmen/src/lib.rs

Co-authored-by: Alexander Popiak <alexander.popiak@parity.io>

* Fix all tests

* Fix everything

* Add note

Co-authored-by: Alexander Popiak <alexander.popiak@parity.io>

* Doc update

* Fix some complexity params

* Once more ready to benchmark

* ready for bench

* final tunes

* Update frame/elections-phragmen/src/lib.rs

* Fix fix

* Update frame/elections-phragmen/src/lib.rs

* Update frame/elections-phragmen/src/benchmarking.rs

Co-authored-by: Alexander Popiak <alexander.popiak@parity.io>

* Update frame/elections-phragmen/src/benchmarking.rs

Co-authored-by: Alexander Popiak <alexander.popiak@parity.io>

* Update to latest weights

* Some fixes

* Fix dual voter read from @thiolliere

* Remove todos

* review from @shawntabrizi



* Fix bench tests.

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>
Co-authored-by: Alexander Popiak <alexander.popiak@parity.io>