REORG: mux-quic: rename stream initialization function

Rename both qcc_open_stream_local/remote() functions to
qcc_init_stream_local/remote(). This change is purely cosmetic. It will
reduces the ambiguity with the soon to be implemented OPEN states for
QCS instances.
diff --git a/src/h3.c b/src/h3.c
index eb930af..0740166 100644
--- a/src/h3.c
+++ b/src/h3.c
@@ -1081,7 +1081,7 @@
 	struct h3c *h3c = ctx;
 	struct qcs *qcs;
 
-	qcs = qcc_open_stream_local(h3c->qcc, 0);
+	qcs = qcc_init_stream_local(h3c->qcc, 0);
 	if (!qcs)
 		return 0;