Show help banner when Cloudflare captcha page is shown in WebView

(cherry picked from commit 6d69caf59e277a2185c1a851ffad8a00a4a93a30)

core/src/main/java/eu/kanade/tachiyomi/network/interceptor/CloudflareInterceptor.kt

@@ -44,7 +44,7 @@ class CloudflareInterceptor(
         // Because OkHttp's enqueue only handles IOExceptions, wrap the exception so that
         // we don't crash the entire app
         catch (e: CloudflareBypassException) {
-            throw IOException(context.getString(R.string.information_cloudflare_bypass_failure))
+            throw IOException(context.getString(R.string.information_cloudflare_bypass_failure), e)
         } catch (e: Exception) {
             throw IOException(e)
         }

core/src/main/java/eu/kanade/tachiyomi/util/system/WebViewUtil.kt

@@ -6,8 +6,10 @@ import android.content.pm.PackageManager
 import android.webkit.CookieManager
 import android.webkit.WebSettings
 import android.webkit.WebView
+import kotlinx.coroutines.suspendCancellableCoroutine
 import logcat.LogPriority
 import tachiyomi.core.util.system.logcat
+import kotlin.coroutines.resume
 
 object WebViewUtil {
     const val SPOOF_PACKAGE_NAME = "org.chromium.chrome"
@@ -32,6 +34,10 @@ fun WebView.isOutdated(): Boolean {
     return getWebViewMajorVersion() < WebViewUtil.MINIMUM_WEBVIEW_VERSION
 }
 
+suspend fun WebView.getHtml(): String = suspendCancellableCoroutine {
+    evaluateJavascript("document.documentElement.outerHTML") { html -> it.resume(html) }
+}
+
 @SuppressLint("SetJavaScriptEnabled")
 fun WebView.setDefaultSettings() {
     with(settings) {