Remove 3-argument `{_,}evaluate!!`; clean up submodel code#960

penelopeysm merged 6 commits intobreakingTuringLang/DynamicPPL.jl:breakingfrom

py/no-context-evaluate-submodelTuringLang/DynamicPPL.jl:py/no-context-evaluate-submodelCopy head branch name to clipboard