Move network fuzzers from //testing/libfuzzer/fuzzers to //net

testing/libfuzzer/fuzzers/unescape_url_component_fuzzer.cc

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <string>
-
-#include "net/base/escape.h"
-
-static const int kMaxUnescapeRule = 31;
-
-// Entry point for LibFuzzer.
-extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  std::string path(reinterpret_cast<const char*>(data), size);
-  for (int i = 0; i <= kMaxUnescapeRule; i++) {
-    (void)net::UnescapeURLComponent(path,
-                                    static_cast<net::UnescapeRule::Type>(i));
-  }
-  return 0;
-}