fix IndexFieldMetadata availability in IndexMetadata/ObjectMetadata in front (#12886)

Context : 
- IndexFieldMetadata was no longer available on 'objects' gql query
([since this PR](https://github.com/twentyhq/twenty/pull/12785)). Then,
unicity checks on import do not work anymore.

Fix : 
- Add a dataloader logic in indexFieldMetadata
- Add extra check in unicity hook on import

packages/twenty-server/src/engine/core-modules/record-transformer/utils/transform-links-value.util.ts

@@ -1,7 +1,9 @@
 import { isNonEmptyString } from '@sniptt/guards';
-import { isDefined } from 'twenty-shared/utils';
+import {
+  isDefined,
+  lowercaseUrlAndRemoveTrailingSlash,
+} from 'twenty-shared/utils';
 
-import { lowercaseDomainAndRemoveTrailingSlash } from 'src/engine/api/graphql/workspace-query-runner/utils/query-runner-links.util';
 import { removeEmptyLinks } from 'src/engine/core-modules/record-transformer/utils/remove-empty-links';
 import { LinkMetadataNullable } from 'src/engine/metadata-modules/field-metadata/composite-types/links.composite-type';
 
@@ -46,14 +48,14 @@ export const transformLinksValue = (
   return {
     ...value,
     primaryLinkUrl: isDefined(primaryLinkUrl)
-      ? lowercaseDomainAndRemoveTrailingSlash(primaryLinkUrl)
+      ? lowercaseUrlAndRemoveTrailingSlash(primaryLinkUrl)
       : primaryLinkUrl,
     primaryLinkLabel,
     secondaryLinks: JSON.stringify(
       secondaryLinks?.map((link) => ({
         ...link,
         url: isDefined(link.url)
-          ? lowercaseDomainAndRemoveTrailingSlash(link.url)
+          ? lowercaseUrlAndRemoveTrailingSlash(link.url)
           : link.url,
       })),
     ),