Abstracts elections-phragmen pallet to use NposSolver (#12588)

* Abstracts elections-phragmen pallet to use NposSolver

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

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

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

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

* changes the name of the pallet; adds changelog

* update changelog

* Adds weight testing

* Adds log macro_rules

* renames elections-phragment dir to elections

* weights rename

* fixes typo in cargo toml

* pre/post solve weight scafolding

* refactor do_post_election

* refactors into pre and post election solve for independent benchmarking

* deconstructs PreElectionResults struct

* updates benchmarking pre and post election solve; mock weights

* Update frame/elections/src/lib.rs

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

* Update frame/elections/src/lib.rs

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

* addresses PR comments

* adds pre_solve and post_sove weights

* Adds comments on election pallet id param name change

* ".git/.scripts/bench-bot.sh" pallet dev pallet_elections

* Finishes pre-post solve weights

* Update frame/elections/src/lib.rs

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

* Update frame/elections/src/lib.rs

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>

* Addresses PR comments: no panic in on_init path; nits

* Fixes node build

* Implements approval voting to use as a `NposSolver` (#13367)

* Implements the approval voting methods in sp_npos_elections

* fmt

* remove unecessary file

* comment clarification

* re-run weights

* fix typo

* updates MaxVoters in tests for integrity_tests to pass

* Refactors election provider support benchmarks outside its own crate (#13431)

* Refactors election provider support benchmarks outside its own crate
---------

Co-authored-by: command-bot <>

---------

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
Co-authored-by: parity-processbot <>
Co-authored-by: Ross Bulat <ross@parity.io>