message: Give private members lower suggestion priority
  Currently private member suggestions are interspersed with public ones and are rarely needed. Most implementations (e.g. pyright's sortText, pycharm) give lower priority to them.
diff: @@ -129,7 +129,8 @@ async function provideCompletionItem(document: LinesTextDocument, position: Posi
  const items = Array.isArray(result) ? result : result.items;
  items.map((x) => delete x.sortText);
  - items.sort((a, b) => (a.kind && b.kind ? a.kind - b.kind : 0));
  + const privateLevel = (x) => (x.insertText || x.label).match(/^_*/)[0].length;
  + items.sort((a, b) => (privateLevel(a) - privateLevel(b) || (a.kind && b.kind ? a.kind - b.kind : 0)));
  const snippetSupport = workspace.getConfiguration('pyright').get<boolean>('completion.snippetSupport');
  if (snippetSupport) {
  