Update Protobuf and add protos for CS2 (#176)

* Replace protobuf 2.6.1 with 3.21.8

* Update/add protobuf libs

* Add CS2 protos

* Remove old csgo/dota protos

* Add versioned protoc bin

* Comment out Valve's `schema` define for now

* Use ENetworkDisconnectionReason

* Fix-up `offsetof` to avoid errors on some Clang versions

thirdparty/protobuf-3.21.8/python/google/protobuf/internal/api_implementation.cc

@@ -0,0 +1,111 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#define PY_SSIZE_T_CLEAN
+#include <Python.h>
+
+namespace google {
+namespace protobuf {
+namespace python {
+
+// Version constant.
+// This is either 0 for python, 1 for CPP V1, 2 for CPP V2.
+//
+// 0 is default and is equivalent to
+//   PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=python
+//
+// 1 is set with -DPYTHON_PROTO2_CPP_IMPL_V1 and is equivalent to
+//   PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=cpp
+// and
+//   PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION=1
+//
+// 2 is set with -DPYTHON_PROTO2_CPP_IMPL_V2 and is equivalent to
+//   PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=cpp
+// and
+//   PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION_VERSION=2
+#ifdef PYTHON_PROTO2_CPP_IMPL_V1
+#error "PYTHON_PROTO2_CPP_IMPL_V1 is no longer supported."
+#else
+#ifdef PYTHON_PROTO2_CPP_IMPL_V2
+static int kImplVersion = 2;
+#else
+#ifdef PYTHON_PROTO2_PYTHON_IMPL
+static int kImplVersion = 0;
+#else
+
+static int kImplVersion = -1;  // -1 means "Unspecified by compiler flags".
+
+#endif  // PYTHON_PROTO2_PYTHON_IMPL
+#endif  // PYTHON_PROTO2_CPP_IMPL_V2
+#endif  // PYTHON_PROTO2_CPP_IMPL_V1
+
+static const char* kImplVersionName = "api_version";
+
+static const char* kModuleName = "_api_implementation";
+static const char kModuleDocstring[] =
+    "_api_implementation is a module that exposes compile-time constants that\n"
+    "determine the default API implementation to use for Python proto2.\n"
+    "\n"
+    "It complements api_implementation.py by setting defaults using "
+    "compile-time\n"
+    "constants defined in C, such that one can set defaults at compilation\n"
+    "(e.g. with blaze flag --copt=-DPYTHON_PROTO2_CPP_IMPL_V2).";
+
+static struct PyModuleDef _module = {PyModuleDef_HEAD_INIT,
+                                     kModuleName,
+                                     kModuleDocstring,
+                                     -1,
+                                     nullptr,
+                                     nullptr,
+                                     nullptr,
+                                     nullptr,
+                                     nullptr};
+
+extern "C" {
+PyMODINIT_FUNC PyInit__api_implementation() {
+  PyObject* module = PyModule_Create(&_module);
+  if (module == nullptr) {
+    return nullptr;
+  }
+
+  // Adds the module variable "api_version".
+  if (PyModule_AddIntConstant(module, const_cast<char*>(kImplVersionName),
+                              kImplVersion)) {
+    Py_DECREF(module);
+    return nullptr;
+  }
+
+  return module;
+}
+}
+
+}  // namespace python
+}  // namespace protobuf
+}  // namespace google