global variables (such as IRB date range) set in @connect from TRDW.json

[clarkevans]

It'd be nice to have a way to specify global "variables" that could be accessed deep inside the nested combinator call chain without propagating them as parameters, or making global functions with external state that FunSQL doesn't know about. An example would be IRB date range, which (if set) would be a hard filter on many queries. There is also the project and case numbers that are relevant, among others.