bazel: Add initial config for binary distribution (see #3757)

Add support for building the CEF binary distribution using Bazel
and the default platform toolchain. Tested to work for Windows
x64, MacOS ARM64 and x64 (cross-compile from ARM64), and
Linux x64. Windows x86 (cross-compile from x64) is known to
be broken, see https://github.com/bazelbuild/bazel/issues/22164.

Includes minor changes to tests directory structure to meet
Bazel build requirements.

bazel/win/wrapper.py.tpl

@@ -0,0 +1,69 @@
+# Copyright (c) 2024 The Chromium Embedded Framework Authors. All rights
+# reserved. Use of this source code is governed by a BSD-style license that
+# can be found in the LICENSE file.
+
+import os
+import subprocess
+import sys
+from rules_python.python.runfiles import runfiles
+
+REPLACEMENTS = {
+  "XXX_GETCWD_XXX": os.getcwd(),
+}
+
+def replace_in_str(input):
+  output = input
+  for placeholder, replacement in REPLACEMENTS.items():
+    if placeholder in output:
+      output = output.replace(placeholder, replacement)
+  return output
+
+def print_error(str):
+  print(str, file=sys.stderr)
+
+r = runfiles.Create()
+wrapped_binary = r.Rlocation("winsdk/${binary}")
+args = list(map(replace_in_str, sys.argv[1:]))
+
+# Optionally execute a script before tool execution.
+if args[0].endswith('.bat') or args[0].endswith('.cmd'):
+  if sys.platform != 'win32':
+    raise RuntimeError("Error running bat file; unsupported platform")
+
+  # Execute the .bat file first.
+  bat_file = args[0].replace('/', '\\')
+  p = subprocess.run(
+      bat_file, shell=True,
+      stdout = subprocess.PIPE,
+      stderr = subprocess.STDOUT,
+      text=True)
+  if p.returncode != 0:
+    print_error("[Generated python wrapper] Error running bat file:")
+    print_error(f"CWD: {os.getcwd()}")
+    print_error(f"EXEC: {bat_file}")
+    print_error(f"Exec output:")
+    print_error(p.stdout)
+    raise RuntimeError(f"Error running bat file; {bat_file}")
+
+  args = args[1:]
+
+try:
+  p = subprocess.run(
+      [wrapped_binary] + args,
+      stdout = subprocess.PIPE,
+      stderr = subprocess.STDOUT,
+      text=True)
+  if p.returncode != 0:
+    print_error("[Generated python wrapper] Error running command:")
+    print_error(f"CWD: {os.getcwd()}")
+    print_error(f"EXEC: {wrapped_binary}")
+    print_error(f"ARGS: {args}")
+    print_error(f"Exec output:")
+    print_error(p.stdout)
+    raise RuntimeError(f"Error running wrapped command; {wrapped_binary}")
+except OSError as e:
+  print_error("[Generated python wrapper] Error running command:")
+  print_error(f"CWD: {os.getcwd()}")
+  print_error(f"EXEC: {wrapped_binary}")
+  print_error(f"ARGS: {args}")
+  raise