fix SortByFn type (#42510)
fix SortByFn type (#42510)

* fix SortByFn type

Added boolean for sort order.

* Made new parameter optional

mcliment/DefinitelyTyped,dsebastien/DefinitelyTyped,georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped,dsebastien/DefinitelyTyped,georgemarshall/DefinitelyTyped,markogresak/DefinitelyTyped