Consolidate checks on the classification `type`

[hfrick]

We can consolidate something here:

set_tailor_type() updates the type based on the outcome, while update_type() determines the classification type from the number of probability columns, i.e., from the predictors. Both are being called only in fit.tailor().

tailor/R/tailor.R

Lines 286 to 308 in b5e1325

	set_tailor_type <- function(object, y, call = caller_env()) {
	if (object$type != "unknown") {
	check_variable_type(y, object$type, "outcome", call = call)
	return(object)
	}
	if (is.factor(y)) {
	lvls <- levels(y)
	if (length(lvls) == 2) {
	object$type <- "binary"
	} else {
	object$type <- "multiclass"
	}
	} else if (is.numeric(y)) {
	object$type <- "regression"
	} else {
	cli_abort(
	"Only factor and numeric outcomes are currently supported.",
	call = call
	)
	}
	object
	}

tailor/R/validation-rules.R

Lines 129 to 136 in b5e1325

	update_type <- function(type, probabilities) {
	if (type == "binary") {
	if (length(probabilities) > 2) {
	type <- "multiclass"
	}
	}
	type
	}