formatting of nep-18 compatible arrays with assert_* #3616
Description
At the moment, the formatting.diff_*_repr functions that provide the pretty-printing for assert_* use repr to format NEP-18 strings, truncating the result if it is too long. In the case of pint's quantities, this makes the pretty printing useless since only a few values are visible and the unit is in the truncated part.
What should we about this? Does pint have to change its repr?
xref #3611