misc/mc: update Midnight Commander to the latest version 4.8.33
- Tentatively switch default renderer from S-Lang to ncurses which is part of the base system and does not pull EoLed `devel/pcre'
- GC no longer needed USES+=shebangfix, adjust Python dependency
- Add support for entering and viewing FreeBSD packages, based on the idea and patch by Walter von Entferndt
- Register installation conflict with `misc/mc6' port while at it
PR: 292865, 293259, 294086