Fix: assorted next fixes (#42634)

* chore: fix slightly broken package.json

* fix: update children type

* fix: make size optional for Spacer

* fix: correct broken env import

* test: update snapshot and fix typing

* test: fix imports and remove old snapshot

client/src/components/helpers/spacer.tsx

@@ -1,7 +1,7 @@
 import React from 'react';
 
 interface SpacerProps {
-  size: number;
+  size?: number;
 }
 
 const styles = { padding: '15px 0', height: '1px' };