yin parser CHANGE support for extension in substatements of uses

includes upport for grouping and uses's refine
diff --git a/src/resolve.c b/src/resolve.c
index 4785be4..15e8ef9 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -4889,7 +4889,8 @@
             }
             for (k = 0, j = *old_size; k < rfn->must_size; k++, j++) {
                 must[j].ext_size = rfn[k].ext_size;
-                lys_extension_instances_dup(rfn->must[k].ext, rfn->must[k].ext_size, &must[j].ext);
+                lys_ext_dup(ctx, rfn->must[k].ext, rfn->must[k].ext_size, &rfn->must[k], LYEXT_PAR_RESTR,
+                            &must[j].ext, unres);
                 must[j].expr = lydict_insert(ctx, rfn->must[k].expr, 0);
                 must[j].dsc = lydict_insert(ctx, rfn->must[k].dsc, 0);
                 must[j].ref = lydict_insert(ctx, rfn->must[k].ref, 0);