Update all .cpp files to use .cc extension (google style)

pipeline/src/web_client/curl_web_client_url_encode.cc

@@ -0,0 +1,24 @@
+/**
+ * @file web_client/curl_web_client_url_encode.cc
+ * @brief CURLWebClient::UrlEncode() implementation.
+ */
+
+#include <curl/curl.h>
+
+#include <stdexcept>
+#include <string>
+
+#include "web_client/curl_web_client.h"
+
+std::string CURLWebClient::UrlEncode(const std::string& value) {
+  // A NULL handle is fine for UTF-8 encoding according to libcurl docs.
+  char* output = curl_easy_escape(nullptr, value.c_str(), 0);
+
+  if (!output) {
+    throw std::runtime_error("[CURLWebClient] curl_easy_escape failed");
+  }
+
+  std::string result(output);
+  curl_free(output);
+  return result;
+}