devel/lstr: Add lstr 0.2.1

A fast, minimalist directory tree viewer, written in Rust. Inspired by the
command line program tree, with a powerful interactive mode.

Features:
- Classic and interactive modes: Use lstr for a classic tree-like view, or
  launch lstr interactive for a fully interactive TUI.
- Theme-aware coloring: Respects your system's LS_COLORS environment variable
  for fully customizable file and directory colors.
- Rich information display (optional):
  - Display file-specific icons with --icons (requires a Nerd Font).
  - Show file permissions with -p.
  - Show file sizes with -s.
  - Git Integration: Show file statuses (Modified, New, Untracked, etc.)
    directly in the tree with the -G flag.
- Smart filtering:
  - Respects your .gitignore files with the -g flag.
  - Control recursion depth (-L) or show only directories (-d).