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>

doc/long-help.txt

@@ -61,8 +61,8 @@ Options:
           Set the tab width to T spaces. Use a width of 0 to pass tabs through directly
 
       --wrap <mode>
-          Specify the text-wrapping mode (*auto*, never, character). The '--terminal-width' option
-          can be used in addition to control the output width.
+          Specify the text-wrapping mode (*auto*, never, character, word). The '--terminal-width'
+          option can be used in addition to control the output width.
 
   -S, --chop-long-lines
           Truncate all lines longer than screen width. Alias for '--wrap=never'.

doc/short-help.txt

@@ -26,7 +26,7 @@ Options:
       --tabs <T>
           Set the tab width to T spaces.
       --wrap <mode>
-          Specify the text-wrapping mode (*auto*, never, character).
+          Specify the text-wrapping mode (*auto*, never, character, word).
   -S, --chop-long-lines
           Truncate all lines longer than screen width. Alias for '--wrap=never'.
   -n, --number