Enhancement: Consolidation of standardization

[mboyas-mitre]

openVA/openVA/R/stackplot.r

Lines 112 to 118 in f16a333

	if(class(x[[i]]) == "interVA" || class(x[[i]]) == "interVA5" ){
	counts[i] <- length(x[[i]]$VA)
	}else if(class(x[[i]]) == "tariff"){
	counts[i] <- dim(x[[i]]$causes.test)[1]
	}else if(class(x[[i]]) == "nbc"){
	counts[i] <- dim(x[[i]]$test)[1]
	}

There is a lot of effort done - in stackplot as well as the other functions in openVA, and not just this segment of lines - to standardize the output of the algorithm packages. Doing this as one-offs in every function seems repetitive, hard to maintain, and is hard to read. We propose splitting out the standardization into a single function that can transform outputs from all of the algorithms to a standard format, and this function can be called in almost every other workflow in openVA before running specific plotting code, etc.