Convert Q-Q plot to use multi-model cycling more effectively

[jfrost-mo]

What problem does your feature request solve?

Converting the recipes in #765 that one that causes me the most trouble was the basic QQ plot. This is due to it talking quite a lot of inputs, and having its own cycling built in. I did a minimal conversion, however it now acts quite differently from the other operators. I'd like to convert it, but it needed more attention, thus I have broken it into its own issue.

Describe the solution you'd like

Not sure yet. Need to figure out what we might want to plot with it, and how it relates to plots involving multiple models.

Describe alternatives you've considered

Ditch the QQ plot? It seems quite useful though, so I don't want to do that.