Re #10681 Initial commit. Mari Reduction wrapped (almost)
Re #10681 Fully extracted Mari Reduction

and system tests work fine.
Re #10681 Modified MAPS system test
Re #10681 Merlin system test moved to redWrapper
Re #10681 Converted Let single rep
Re #10681 Converted LET reduction to reduction wrapper
Merge remote-tracking branch 'origin/feature/10681_RedWrapper'