Improve lazy loading (#12393)

Creating manual chunk was a bad idea, we should always solve lazy
loading problem at the source instance.

Setting a 4.5MB for the index bundle size, CI will fail if we go above.

There is still a lot of room for optimizations!
- More agressive lazy loading (e.g. xyflow and tiptap are still loaded
in index!)
- Add a  prefetch mechanism
- Add stronger CI checks to make sure libraries we've set asides are not
added back
- Fix AllIcons component with does not work as intended (loaded on
initial load)

packages/twenty-front/src/modules/object-metadata/hooks/useLoadMockedObjectMetadataItems.ts

@@ -1,13 +1,16 @@
 import { isAppWaitingForFreshObjectMetadataState } from '@/object-metadata/states/isAppWaitingForFreshObjectMetadataState';
 import { objectMetadataItemsState } from '@/object-metadata/states/objectMetadataItemsState';
 import { useRecoilCallback } from 'recoil';
-import { generatedMockObjectMetadataItems } from '~/testing/mock-data/generatedMockObjectMetadataItems';
 import { isDeeplyEqual } from '~/utils/isDeeplyEqual';
 
 export const useLoadMockedObjectMetadataItems = () => {
   const loadMockedObjectMetadataItems = useRecoilCallback(
     ({ set, snapshot }) =>
-      () => {
+      async () => {
+        const { generatedMockObjectMetadataItems } = await import(
+          '~/testing/mock-data/generatedMockObjectMetadataItems'
+        );
+
         if (
           !isDeeplyEqual(
             snapshot.getLoadable(objectMetadataItemsState).getValue(),