feat: add a "match success rate" plot

[jdhoffa]

@jacobvjk and I were talking, and this is something that seems to have been useful for supervisor projects, however, this seems like a useful exported function from r2dii.plot.

See function here: https://github.com/RMI-PACTA/workflow.aggregate.loanbooks/blob/cbf818d5467bd37506816c6cceb89497bb37028d/R/plots.R#L464

[jacobvjk]

as mentioned here: RMI-PACTA/pacta.multi.loanbook#236

I think there is an argument for making the match success rate available in r2dii.plot so that it can be used in individual analyses in low threshold way. I am thinking IFC applications for example. It would also be good to have something like that available if/when we set up a P4B cookbook. But definitely no urgency right now