add an absolute measure of election score on-chain as a parameter (#8903)

* add an absolute measure of election score on-chain as a parameter

* make it storage item

* line width

* some nits

* Apply suggestions from code review

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

* make a few more things pub

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