Add null coalescing operator `%||%` to be introduced with R 4.4.0

[realHenningLorenzen]

Reference

https://cloud.r-project.org/bin/windows/base/NEWS.R-4.4.0rc.html

L %||% R newly in base is an expressive idiom for the phrases if(!is.null(L)) L else R or if(is.null(L)) R else L.

[olivroy]

there is also sort_by()