sysutils/ictree: [NEW PORT] Like tree(1) but interactive

ictree is a terminal-based program that takes a list of contents of
directories and displays them in a pager similar to less where you can
fold/unfold

https://nikitaivanovv.github.io/ictree/

PR: 284245
Approved by: yuri@ (Mentor)

Differential Revision: https://reviews.freebsd.org/D52439