Return empty values last in table sorting

Is your feature request related to a problem? Please describe…

When empty data (for example an empty String "") is present in table rows, the sorting function presents this first when sorted in ascending order.

Describe the solution you’d like

Empty fields should be returned last.

Describe alternatives you’ve considered

As I see it, there may be a couple of ways to present the results:

1. Empty fields are always returned last (both in ascending and descending order)
2. Empty fields are returned last when ascending order is selected

This may also be a configurable property to pass.

Additional context

I’m aware that the empty string comes technically before “a” for instance, but presenting a lot of empty data first when sorting is bad UX.

[tmorehouse]

BootstrapVue v2.0.0-rc.28 has been released.

[tmorehouse]

The new sort-null-last now also handles the empty string case as well. setting the prop to true will sort null, undefined, and '' last.