Tweak CSSTransition import to reduce bundle size

src/js/components/form/creators.jsx

@@ -2,7 +2,7 @@ import cx from 'classnames';
 import deepEqual from 'deep-equal';
 import PropTypes from 'prop-types';
 import React, { memo, useCallback, useEffect, useMemo, useRef, useState } from 'react';
-import { CSSTransition } from 'react-transition-group';
+import CSSTransition from 'react-transition-group/cjs/CSSTransition'
 
 import CreatorField from './creator-field';
 import { enumerateObjects } from '../../utils';