science/mctc-lib: Update 0.4.0 => 0.5.0

Changelogs:

• https://github.com/grimme-lab/mctc-lib/releases/tag/v0.4.1
• https://github.com/grimme-lab/mctc-lib/releases/tag/v0.4.2
• https://github.com/grimme-lab/mctc-lib/releases/tag/v0.5.0
• https://github.com/grimme-lab/mctc-lib/compare/v0.4.0...v0.4.1
• https://github.com/grimme-lab/mctc-lib/compare/v0.4.1...v0.4.2
• https://github.com/grimme-lab/mctc-lib/compare/v0.4.2...v0.5.0

• Add WWW for source code repository
• Pet portclippy(1) and portfmt(1)

Approved by: yuri@ (maintainer, Mentor)
Differential Revision: https://reviews.freebsd.org/D53524