Fix String::word_wrap() for long words

- Changes `TextServer.string_get_word_breaks()`
  - Returns pairs of boundary start and end offsets
  - Accepts `chars_per_line` to return line breaks
- Removes `String::word_wrap()`

Co-authored-by: bruvzg <7645683+bruvzg@users.noreply.github.com>

core/string/ustring.h

@@ -425,7 +425,6 @@ public:
 	String c_escape_multiline() const;
 	String c_unescape() const;
 	String json_escape() const;
-	String word_wrap(int p_chars_per_line) const;
 	Error parse_url(String &r_scheme, String &r_host, int &r_port, String &r_path) const;
 
 	String property_name_encode() const;