Consider re-wording non-decreasing value column check message

[lshandross]

Currently the message printed for the non-descending value column check is quite long:

✔ [value_col_non_desc]: Values in `value` column are non-decreasing as output_type_ids increase for all unique task ID value/output type combinations of quantile or cdf output types

It would be clearer if we moved the part about the check only being for quantile and cdf output types to the beginning, as well as prevent misunderstandings if the last part of the message is cut off (or people don't read that far)

[zkamvar]

I'm wondering if we should just take the title of the check documentation: "quantile and cdf output type values of model output data are non-descending"

Or maybe "quantile and cdf output type values of model output data do not decrease"

We can then add more context if there is an error: "quantile and cdf output type values of model output decrease. Values should not decrease with increasing output_type_id values"