More Improvements to Benchmarking CLI + Generic WeightInfo (#7168)

* Generic WeightInfo, Output File Path

* Make `WeightInfo` generic

* Add support for header file

* fix line width

* add `--spaces` flag

* Configurable trait and struct strings

* make elections phragmen generic

* Add date to generated file

* Apply suggestions from code review

Co-authored-by: Gavin Wood <[email protected]>

* fixes

* add settings metadata to output

Co-authored-by: nikvolf <[email protected]>
Co-authored-by: Gavin Wood <[email protected]>