feat(webconnectivitylte): add Cloudflare CAPTCHA test cases (ooni#1476)

## Checklist

- [x] I have read the [contribution
guidelines](https://github.com/ooni/probe-cli/blob/master/CONTRIBUTING.md)
- [x] reference issue for this pull request:
ooni/probe#1734
- [x] if you changed anything related to how experiments work and you
need to reflect these changes in the ooni/spec repository, please link
to the related ooni/spec pull request:
ooni/spec#284
- [x] if you changed code inside an experiment, make sure you bump its
version number: not needed

## Description

Closes ooni/probe#1734.

See ooni/probe#2661.

While there, rename an incorrectly renamed Yandex test.

While there, ignore the `/oonireport` binary.

.gitignore

@@ -23,6 +23,7 @@
 /oohelper
 /oohelperd
 /ooniprobe
+/oonireport
 /ooporthelper
 /probe-cli.cov
 /tinyjafar

internal/experiment/webconnectivityqa/cloudflare.go

@@ -0,0 +1,53 @@
+package webconnectivityqa
+
+import "github.com/ooni/probe-cli/v3/internal/netemx"
+
+// cloudflareCAPTCHAWithHTTP obtains the cloudflare CAPTCHA using HTTP.
+func cloudflareCAPTCHAWithHTTP() *TestCase {
+	// See https://github.com/ooni/probe/issues/2661 for an explanation of why
+	// here for now we're forced to declare "http-diff".
+	return &TestCase{
+		Name:  "cloudflareCAPTCHAWithHTTP",
+		Flags: TestCaseFlagNoV04,
+		Input: "http://www.cloudflare-cache.com/",
+		Configure: func(env *netemx.QAEnv) {
+			// nothing
+		},
+		ExpectErr: false,
+		ExpectTestKeys: &testKeys{
+			DNSConsistency:  "consistent",
+			StatusCodeMatch: false,
+			BodyLengthMatch: false,
+			BodyProportion:  0.18180740037950663,
+			HeadersMatch:    true,
+			TitleMatch:      false,
+			XBlockingFlags:  16, // AnalysisBlockingFlagHTTPDiff
+			Accessible:      false,
+			Blocking:        "http-diff",
+		},
+	}
+}
+
+// cloudflareCAPTCHAWithHTTPS obtains the cloudflare CAPTCHA using HTTPS.
+func cloudflareCAPTCHAWithHTTPS() *TestCase {
+	return &TestCase{
+		Name:  "cloudflareCAPTCHAWithHTTPS",
+		Flags: TestCaseFlagNoV04,
+		Input: "https://www.cloudflare-cache.com/",
+		Configure: func(env *netemx.QAEnv) {
+			// nothing
+		},
+		ExpectErr: false,
+		ExpectTestKeys: &testKeys{
+			DNSConsistency:  "consistent",
+			StatusCodeMatch: false,
+			BodyLengthMatch: false,
+			BodyProportion:  0.18180740037950663,
+			HeadersMatch:    true,
+			TitleMatch:      false,
+			XBlockingFlags:  32, // AnalysisBlockingFlagSuccess
+			Accessible:      true,
+			Blocking:        false,
+		},
+	}
+}

internal/experiment/webconnectivityqa/testcase.go

@@ -42,6 +42,9 @@ func AllTestCases() []*TestCase {
 		badSSLWithWrongServerName(),
 		badSSLWithUnknownAuthorityWithInconsistentDNS(),
 
+		cloudflareCAPTCHAWithHTTP(),
+		cloudflareCAPTCHAWithHTTPS(),
+
 		controlFailureWithSuccessfulHTTPWebsite(),
 		controlFailureWithSuccessfulHTTPSWebsite(),