Sorting undefined/null data

[Diiegoav]

Guidelines

Demo sandbox

• https://codesandbox.io/s/material-table-starter-template-forked-g38sv9?file=/src/index.js

Is your feature request related to a problem? Please describe.
Hi, I would like if we can enhance the sorting of material table, when related to undefined/null values. currently as shown on the code sandbox above, when you have undefined/null values, depending on the order direction sort, sometimes are shown on top, which does not make to much sense, I think they should be always at last.

Describe the solution you'd like
Undefined null values should be sorted always at last of the data.

[Domino987]

Merged, thank you!

[Diiegoav]

@Domino987 based on https://mui.com/x/react-data-grid/ I think could be good idea to replicate their behavior, when ASC empty fields can be updated on top, DESC at last.

Any thoughts ?