`misc/qtchooser` provides a wrapper binary `bin/qtchooser`, that when called with
name `foo`, will lauch the corresponding binary from
`lib/qt${current_qt_version}/bin/foo`.
Previously qtchooser would install a list of 30-ish symlinks to itself automatically.
Now we switch this around.
qt-dist ports that define `QT_BINARIES` will now have a `@postexec` and `@postunexec`
entry added to their plist to run the shell-script `update-qtchooser-wrapper`
(installed by qtchooser).
`update-qtchooser-wrapper` removes all symlinks to `bin/qtcreator` that have no
corresponding binary in `lib/qt*/bin`, and readds links that are missing.
PR: 242905