Move getDefaultConversation into a shared test folder

ts/util/getDefaultConversation.ts

@@ -1,24 +0,0 @@
-// Copyright 2020 Signal Messenger, LLC
-// SPDX-License-Identifier: AGPL-3.0-only
-
-import { v4 as generateUuid } from 'uuid';
-import { ConversationType } from '../state/ducks/conversations';
-
-export function getDefaultConversation(
-  overrideProps: Partial<ConversationType>
-): ConversationType {
-  if (window.STORYBOOK_ENV !== 'react') {
-    throw new Error('getDefaultConversation is for storybook only');
-  }
-
-  return {
-    id: 'guid-1',
-    lastUpdated: Date.now(),
-    markedUnread: Boolean(overrideProps.markedUnread),
-    e164: '+1300555000',
-    title: 'Alice',
-    type: 'direct' as const,
-    uuid: generateUuid(),
-    ...overrideProps,
-  };
-}