japanese/mh: fix build on 16.0-current/15.0-stable and add LICENSE

${WRKSRC}/uip/vmh.c includes <term.h> (a part of ncurses).
And on FreeBSD term.h includes <termios.h> with ncurses-6.5.

But since ncurses-6.6 term.h doesn't include termios/termio/sgttyb headers
and doesn't define some related symbols. These directive has been excluded
with "#ifdef NCURSES_INTERNALS".

PR: 293936
MFH: 2026Q2
See also: https://forums.gentoo.org/viewtopic-t-1100154-start-0-postdays-0-postorder-asc-highlight-.html
Event: Wiesbaden Hackathon 202604

(cherry picked from commit b0f02c542d233b6e9f21db6fe1cfc6ff3e47526f)