support KLV tracks (#808)

Co-authored-by: aler9 <46489434+aler9@users.noreply.github.com>

pkg/format/klv_test.go

@@ -0,0 +1,17 @@
+package format
+
+import (
+	"testing"
+
+	"github.com/pion/rtp"
+	"github.com/stretchr/testify/require"
+)
+
+func TestKLVAttributes(t *testing.T) {
+	format := &KLV{
+		PayloadTyp: 96,
+	}
+	require.Equal(t, "KLV", format.Codec())
+	require.Equal(t, 90000, format.ClockRate())
+	require.Equal(t, true, format.PTSEqualsDTS(&rtp.Packet{}))
+}