games/legendary: New port

Legendary is an open-source game launcher that can download and install
games from the Epic Games platform on Linux, macOS, and Windows. Its
name as a tongue-in-cheek play on tiers of item rarity in many MMORPGs.

Note: Legendary is currently a CLI (command-line interface) application
without a graphical user interface, it has to be run from a terminal.

PR: 272565
Co-authored-by: Kenneth Raplee <kenrap@FreeBSD.org>
Approved by: makc (mentor)