message: [formatting] Rename formattingOptions to options
  LanguageClient-neovim `:call LanguageClient_formatting()` works now
diff: @@ -19,11 +19,11 @@ struct lsTextDocumentFormattingParams {
  lsTextDocumentIdentifier textDocument;
  // The format options, like tabs or spaces.
  - lsFormattingOptions formattingOptions;
  + lsFormattingOptions options;
  };
  MAKE_REFLECT_STRUCT(lsTextDocumentFormattingParams,
  textDocument,
  - formattingOptions);
  + options);
  struct Ipc_TextDocumentFormatting
  : public IpcMessage<Ipc_TextDocumentFormatting> {
  @@ -57,8 +57,8 @@ struct TextDocumentFormattingHandler
  WorkingFile* working_file =
  working_files->GetFileByFilename(file->def->path);
  - int tab_size = request->params.formattingOptions.tabSize;
  - bool insert_spaces = request->params.formattingOptions.insertSpaces;
  + int tab_size = request->params.options.tabSize;
  + bool insert_spaces = request->params.options.insertSpaces;
  const auto clang_format = std::unique_ptr<ClangFormat>(new ClangFormat(
  working_file->filename, working_file->buffer_content,
  