Auto-cleaning affordance in the table

[paddymul]

I would like a way to let the user know which values were changed via auto-cleaning, along with the original value.

To start I would like to highlight values that have been editted with a different color (possibly only half the cell background to work with other highlighting formatters). Next I would like a hover that shows the original value for the cell.

The frontend side of this would be pretty straightforward with these editted cells containing an array of [cleaned, original] instead of just original.

Constructing that array in python would be very expensive. I think the best approach would be to have two columns, for col name of temperature, have the key of temperature be the cleaned value, have an additional column of temperature_orig, Join the column to create the array value in JS.