multimedia/mkvtoolnix: Update to upstream release 69.0.0

Details:

• Fixes and enhancements, see: https://mkvtoolnix.download/doc/NEWS.md
• Consistent use of American English in program options as well as JSON structures. This is a potentially breaking change, but as these have been introduced just recently in 68.0.0 end of May, the expected number of affected users is reasonably low.

MFH: 2022Q3