SelectOption.value and Select.selected has "any" type, but Select.onSelect has "(..., string | number)"

[mvollmer]

When looking at the SelectOption.value and Select.selected properties, I got the impression that one can use any JavaScript value to identify select options, and it indeed works as expected.

But it doesn't type-check: The Select.onSelect property wants a function that takes string | number. I had expected it to also use any.

We have our own variant of your SimpleSelect template, and we would like to make it generic in the type of the option value. This seems to work, except for this little niggle about the type of Select.onSelect.

[mvollmer]

This is our attempt at making SimpleSelect and CheckboxSelect generic: cockpit-project/cockpit#21454