Add integration tests for /metadata + fix relation deletion (#8706)

In this PR

1. Add integration tests for /metadata (master issue:
https://github.com/twentyhq/twenty/issues/8719)
2. Fix relation deletion: index on "from" object was not deleted,
impeding creation of a new relation between the same two objects A and B
after relation between A and B was deleted

packages/twenty-server/test/integration/metadata/suites/utils/objects-metadata-factory.util.ts

@@ -0,0 +1,30 @@
+import gql from 'graphql-tag';
+
+type ObjectsFactoryParams = {
+  gqlFields: string;
+  input: {
+    filter: object;
+    paging: object;
+  };
+};
+
+export const objectsMetadataFactory = ({
+  gqlFields,
+  input,
+}: ObjectsFactoryParams) => ({
+  query: gql`
+      query ObjectsMetadata($filter: objectFilter!, $paging: CursorPaging!) {
+        objects(filter: $filter, paging: $paging) {
+          edges {
+            node {
+               ${gqlFields}
+            }
+          }
+        }
+      }
+    `,
+  variables: {
+    filter: input.filter,
+    paging: input.paging,
+  },
+});