patch 9.1.0422: function echo_string_core() is too long

Problem:  function echo_string_core() is too long
Solution: Refactor into several smaller functions
          (Yegappan Lakshmanan)

closes: #14804

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/vim9class.c b/src/vim9class.c
index 21945fe..f66aa68 100644
--- a/src/vim9class.c
+++ b/src/vim9class.c
@@ -3845,7 +3845,7 @@
  * Return a textual representation of object "obj"
  */
     char_u *
-object_string(
+object2string(
     object_T	*obj,
     char_u	*numbuf,
     int		copyID,