Added --http-upgrade and --direct to ws-test dial, so it can connect to job-search serve or ws-test serve

One of the two is required. --http-upgrade upgrades an HTTP connection to
a WebSocket on /ws, as before, for job-search serve; --url and --origin go
with it. --direct connects straight to ws-test serve over plain TCP, one
JSON message per line, at --addr (default from server.host and
server.port). --ping, --message, --listen and stdin work the same in both
modes. The README's ws-test section explains the two modes.

internal/cli/ws/dial_test.go

@@ -59,7 +59,7 @@ func TestDialPing(t *testing.T) {
 	_, url := wsServer(t)
 
 	out := cmdtest.MustRun(
-		t, newRoot, "dial", "--url", url, "--message", ping,
+		t, newRoot, "dial", "--http-upgrade", "--url", url, "--message", ping,
 	)
 	cmdtest.Contains(
 		t,
@@ -76,7 +76,7 @@ func TestDialPingFlag(t *testing.T) {
 	cmdtest.Setup(t, "")
 	_, url := wsServer(t)
 
-	out := cmdtest.MustRun(t, newRoot, "dial", "--url", url, "--ping")
+	out := cmdtest.MustRun(t, newRoot, "dial", "--http-upgrade", "--url", url, "--ping")
 	cmdtest.Contains(
 		t,
 		out,
@@ -111,7 +111,7 @@ func TestDialPingTimeout(t *testing.T) {
 		t,
 		newRoot,
 		"",
-		"dial", "--url", url, "--ping", "--timeout", "100ms",
+		"dial", "--http-upgrade", "--url", url, "--ping", "--timeout", "100ms",
 	)
 	cmdtest.ErrContains(t, err, "no pong within 100ms")
 }
@@ -124,7 +124,7 @@ func TestDialMessages(t *testing.T) {
 	out := cmdtest.MustRun(
 		t,
 		newRoot,
-		"dial", "--url", url,
+		"dial", "--http-upgrade", "--url", url,
 		"--message", `{"type":"echo","id":"7","payload":{"a":1}}`,
 		"--message", `{"type":"nonsense","id":"8"}`,
 	)
@@ -145,7 +145,7 @@ func TestDialOrigin(t *testing.T) {
 		t,
 		newRoot,
 		"",
-		"dial", "--url", url, "--message", ping,
+		"dial", "--http-upgrade", "--url", url, "--message", ping,
 		"--origin", "https://evil.example",
 	)
 	cmdtest.ErrContains(t, err, "upgrade refused: 403 Forbidden")
@@ -153,7 +153,7 @@ func TestDialOrigin(t *testing.T) {
 	out := cmdtest.MustRun(
 		t,
 		newRoot,
-		"dial", "--url", url, "--message", ping,
+		"dial", "--http-upgrade", "--url", url, "--message", ping,
 		"--origin", "https://admin.example.com",
 	)
 	cmdtest.Contains(t, out, "connected (101 Switching Protocols)")