refactor(editor): ♻️ Undo / Redo buttons + structure refacto

Yet another huge refacto... While implementing undo and redo features I understood that I updated the stored typebot too many times (i.e. on each key input) so I had to rethink it entirely. I also moved around some files.

apps/builder/components/shared/Graph/Nodes/ButtonNode/ButtonNodeOverlay.tsx

@@ -0,0 +1,26 @@
+import { Flex, FlexProps } from '@chakra-ui/react'
+import { ChoiceItem } from 'models'
+import React from 'react'
+
+type Props = {
+  item: ChoiceItem
+} & FlexProps
+
+export const ButtonNodeOverlay = ({ item, ...props }: Props) => {
+  return (
+    <Flex
+      px="4"
+      py="2"
+      rounded="md"
+      bgColor="white"
+      borderWidth="1px"
+      borderColor={'gray.300'}
+      w="212px"
+      pointerEvents="none"
+      shadow="lg"
+      {...props}
+    >
+      {item.content ?? 'Click to edit'}
+    </Flex>
+  )
+}