* Refund call fee for all non-invalid signed submissions

* Clean up

* Fix benchmarks

* Remove reward from struct

* WIP SignedMaxRefunds

* Apply suggestions from code review

* Add test for ejected call_fee refunds

* Add test for number of calls refunded

* Account for read op in mutate

* Apply suggestions from code review

* Add to node runtime

* Don't refund ejected solutions

* Update frame/election-provider-multi-phase/src/lib.rs

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

* Inegrity test SignedMaxRefunds

* Use reward handle to refund call fee

* Fix node runtime build

* Drain in order of submission

* Update frame/election-provider-multi-phase/src/signed.rs

* save

* Update frame/election-provider-multi-phase/src/signed.rs

Co-authored-by: Niklas Adolfsson <niklasadolfsson1@gmail.com>

* Update frame/election-provider-multi-phase/src/signed.rs

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
Co-authored-by: Niklas Adolfsson <niklasadolfsson1@gmail.com>
Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>