matchArg types and their conversion seem unintuitive

[d-callan]

we built this to serve a need in veupathdb/plot.data originally. but in a more generalized context like this one, it may make sense to expand the handled types beyond character and logical? seems slightly arbitrary. also, the support of multiple types means its possible to pass choices like c(1, 'a', as.Date('2021-12-25'), FALSE) which we should decide what wed like to do about.. base R will just convert those all to character but is that clear to a user of matchArg?