Implement `--matchdirs` flag from tree

```
--matchdirs
        If a match pattern is specified by the -P option, this will cause the pattern to be applied to directory names (in  addition  to  filenames).   In  the
        event  of a match on the directory name, matching is disabled for the directory's contents. If the --prune option is used, empty folders that match the
        pattern will not be pruned.
```