refactor: migrate apitool from netx to netxlite (#496)

I discovered which transport were used by apitool and made sure he gets the same transports now. While there, I discovered an issue with ooni/oohttp that has been fixed with https://github.com/ooni/oohttp/commit/cba9b1ce5ecf7a20217ad8571ad7a85e490c4789.

Part of https://github.com/ooni/probe/issues/1591

internal/engine/netx/httptransport/useragent.go

@@ -1,19 +1,9 @@
 package httptransport
 
-import "net/http"
+import (
+	"github.com/ooni/probe-cli/v3/internal/netxlite"
+)
 
 // UserAgentTransport is a transport that ensures that we always
 // set an OONI specific default User-Agent header.
-type UserAgentTransport struct {
-	RoundTripper
-}
-
-// RoundTrip implements RoundTripper.RoundTrip
-func (txp UserAgentTransport) RoundTrip(req *http.Request) (*http.Response, error) {
-	if req.Header.Get("User-Agent") == "" {
-		req.Header.Set("User-Agent", "miniooni/0.1.0-dev")
-	}
-	return txp.RoundTripper.RoundTrip(req)
-}
-
-var _ RoundTripper = UserAgentTransport{}
+type UserAgentTransport = netxlite.UserAgentTransport

internal/engine/netx/httptransport/useragent_test.go

@@ -1,51 +0,0 @@
-package httptransport_test
-
-import (
-	"net/http"
-	"net/url"
-	"testing"
-
-	"github.com/ooni/probe-cli/v3/internal/engine/netx/httptransport"
-)
-
-func TestUserAgentWithDefault(t *testing.T) {
-	txp := httptransport.UserAgentTransport{
-		RoundTripper: httptransport.FakeTransport{
-			Resp: &http.Response{StatusCode: 200},
-		},
-	}
-	req := &http.Request{URL: &url.URL{
-		Scheme: "https",
-		Host:   "www.google.com",
-		Path:   "/",
-	}}
-	req.Header = http.Header{}
-	resp, err := txp.RoundTrip(req)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if resp.Request.Header.Get("User-Agent") != "miniooni/0.1.0-dev" {
-		t.Fatal("not the User-Agent we expected")
-	}
-}
-
-func TestUserAgentWithExplicitValue(t *testing.T) {
-	txp := httptransport.UserAgentTransport{
-		RoundTripper: httptransport.FakeTransport{
-			Resp: &http.Response{StatusCode: 200},
-		},
-	}
-	req := &http.Request{URL: &url.URL{
-		Scheme: "https",
-		Host:   "www.google.com",
-		Path:   "/",
-	}}
-	req.Header = http.Header{"User-Agent": []string{"antani-client/0.1.1"}}
-	resp, err := txp.RoundTrip(req)
-	if err != nil {
-		t.Fatal(err)
-	}
-	if resp.Request.Header.Get("User-Agent") != "antani-client/0.1.1" {
-		t.Fatal("not the User-Agent we expected")
-	}
-}