x11/rofi-calc: create port

rofi plugin that uses libqalculate's qalc to parse natural language
input and provide results.

Since this uses libqalculate's amazing qalc you can try natural language
queries such 500 + 25% or 5000 EUR to USD or 150 to hex. It can also
solve linear equations on the fly. Try 60x + 30 = 50, for instance.

WWW: https://github.com/svenstaro/rofi-calc

PR: 238028
Submitted by: Alexander Sieg <alex@xanderio.de>