libyang CHANGE use LY_ARRAY_SIZE_TYPE for iterator variables in LY_TREE_FOR

Because of the change in sized arrays design (780ade2101), also the
iterators and other variables used with LY_TREE_FOR or LY_TREE_SIZE
should be of LY_ARRAY_SIZE_TYPE.

Also the new LY_PRI_ARRAY_SIZE_TYPE was introduced to correctly print
the value of this type in a formatted print functions.
diff --git a/src/parser_yang.c b/src/parser_yang.c
index 99b3e87..d260cc0 100644
--- a/src/parser_yang.c
+++ b/src/parser_yang.c
@@ -815,7 +815,7 @@
  */
 static LY_ERR
 parse_ext(struct lys_yang_parser_ctx *ctx, const char **data, const char *ext_name, int ext_name_len, LYEXT_SUBSTMT insubstmt,
-          uint32_t insubstmt_index, struct lysp_ext_instance **exts)
+          LY_ARRAY_SIZE_TYPE insubstmt_index, struct lysp_ext_instance **exts)
 {
     LY_ERR ret = LY_SUCCESS;
     char *buf, *word;