vim-patch:8.2.4932: not easy to filter the output of maplist()

Problem:    Not easy to filter the output of maplist().
Solution:   Add mode_bits to the dictionary. (Ernie Rael, closes vim/vim#10356)

d8f5f76621

Co-authored-by: Ernie Rael <errael@raelity.com>

src/nvim/mapping.c

@@ -2125,6 +2125,7 @@ static Dictionary mapblock_fill_dict(const mapblock_T *const mp, const char *lhs
   }
   PUT(dict, "mode", CSTR_AS_OBJ(mapmode));
   PUT(dict, "abbr", INTEGER_OBJ(abbr ? 1 : 0));
+  PUT(dict, "mode_bits", INTEGER_OBJ(mp->m_mode));
 
   return dict;
 }