Add word wrapping mode (#3597)

* feat: add word wrapping mode for --wrap flag

* Run `cargo fmt` and add CHANGELOG entry

* Add word wrap tests, update manpage and shell completions

- Add integration tests for word wrapping: basic word boundary breaking,
  fallback to character wrapping for long words, line numbers, and
  short lines that fit without wrapping
- Update manpage to document the new 'word' wrapping mode
- Update bash, fish, zsh, and PowerShell completions with 'word' option
- Avoid unnecessary clone of `line_buf` when word wrap is disabled

* make clippy and cargo fmt happy

---------

Co-authored-by: Keith Hall <keith-hall@users.noreply.github.com>

tests/examples/word-wrap.txt

@@ -0,0 +1,3 @@
+The quick brown fox jumps over the lazy dog and then runs away
+superlongwordthatdefinitelyexceedstheterminalwidthandshouldfallbacktocharacterwrapping
+short words here