graphics/R-cran-cowplot: New port: Streamlined Plot Theme and Plot Annotations for 'ggplot2'

• Submitter becomes maintainer

Provides various features that help with creating publication-quality figures
with 'ggplot2', such as a set of themes, functions to align plots and arrange
them into complex compound figures, and functions that make it easy to annotate
plots and or mix plots with images.
The package was originally written for internal use in the Wilke lab, hence the
name (Claus O. Wilke's plot package).
It has also been used extensively in the book Fundamentals of Data
Visualization.

WWW: https://wilkelab.org/cowplot/

Differential Revision: https://reviews.freebsd.org/D43735