science/cpcmx: [NEW PORT] Extended conductor-like polarizable continuum solvation model

This is an fully Free Software solvation model, based on the original
conductor like screening model for realistic solvation (COSMO-RS)
model by Klamt et al. in combination with the universal solvation
model based on solute electron density (SMD): by Marenich, Cramer and
Truhlar.

WWW: https://github.com/grimme-lab/CPCM-X/

Reviewed by: diizzy@
Approved by: yuri@ (Mentor)
Differential Revision: https://reviews.freebsd.org/D53531