des_func_quantile: Test desirability functions
In CollinErickson/GradAdaptCompExp: Gradient Adaptive Computer Experiments

A des func where output is scaled 0 to 1, max higher

des_func_quantile(
  mod,
  XX,
  threshold = 0,
  power = 1,
  return_se = F,
  N_add = 1000,
  threshold_jump = 0
)

`mod`	GP model
`XX`	Points to evaluate at
`threshold`	Scalar in [0,1) thresholding how big the quantile should be.
`power`	The power the quantiles will be raised to after thresholding.
`return_se`	whether the se prediction should be returned along with the des, all will be returned in data.frame, this will save time if calculating the werror function since it is faster to predict both at once instead of separately
`N_add`	Number of points to add
`threshold_jump`	Parameter, leave as 0