Add useGroupBy hook + update calendar view to use groupBy (#15439)

## Context
Took inspiration from findMany + kanban => Implemented a hook for the
new groupBy API endpoints
Fixed an issue when DnD to an empty day

packages/twenty-front/src/modules/object-record/cache/utils/__tests__/createCacheEdgeWithRecordRef.test.ts

@@ -0,0 +1,69 @@
+import { type Reference } from '@apollo/client';
+
+import { encodeCursor } from '@/apollo/utils/encodeCursor';
+import { type ObjectMetadataItem } from '@/object-metadata/types/ObjectMetadataItem';
+import { type RecordGqlNode } from '@/object-record/graphql/types/RecordGqlNode';
+import { type ToReferenceFunction } from '@apollo/client/cache/core/types/common';
+
+import { createCacheEdgeWithRecordRef } from '../createCacheEdgeWithRecordRef';
+
+describe('createCacheEdgeWithRecordRef', () => {
+  it('should create an edge with reference when toReference returns a reference', () => {
+    // Given
+    const record: RecordGqlNode = {
+      __typename: 'Person',
+      id: '123',
+    };
+
+    const objectMetadataItem = {
+      nameSingular: 'person',
+    } as ObjectMetadataItem;
+
+    const mockReference: Reference = {
+      __ref: 'Person:123',
+    };
+
+    const toReference: ToReferenceFunction = jest.fn(() => mockReference);
+
+    // When
+    const result = createCacheEdgeWithRecordRef({
+      record,
+      objectMetadataItem,
+      toReference,
+    });
+
+    // Then
+    expect(result).not.toBeNull();
+    expect(result).toEqual({
+      __typename: 'PersonEdge',
+      node: mockReference,
+      cursor: encodeCursor(record),
+    });
+    expect(toReference).toHaveBeenCalledWith(record);
+  });
+
+  it('should return null when toReference returns undefined', () => {
+    // Given
+    const record: RecordGqlNode = {
+      __typename: 'Person',
+      id: '123',
+    };
+
+    const objectMetadataItem = {
+      nameSingular: 'person',
+    } as ObjectMetadataItem;
+
+    const toReference: ToReferenceFunction = jest.fn(() => undefined);
+
+    // When
+    const result = createCacheEdgeWithRecordRef({
+      record,
+      objectMetadataItem,
+      toReference,
+    });
+
+    // Then
+    expect(result).toBeNull();
+    expect(toReference).toHaveBeenCalledWith(record);
+  });
+});

packages/twenty-front/src/modules/object-record/cache/utils/createCacheEdgeWithRecordRef.ts

@@ -0,0 +1,30 @@
+import { encodeCursor } from '@/apollo/utils/encodeCursor';
+import { type ObjectMetadataItem } from '@/object-metadata/types/ObjectMetadataItem';
+import { type RecordGqlRefEdge } from '@/object-record/cache/types/RecordGqlRefEdge';
+import { getEdgeTypename } from '@/object-record/cache/utils/getEdgeTypename';
+import { type RecordGqlNode } from '@/object-record/graphql/types/RecordGqlNode';
+import { type ToReferenceFunction } from '@apollo/client/cache/core/types/common';
+import { isDefined } from 'twenty-shared/utils';
+
+type CreateCacheEdgeWithRecordRefParams = {
+  record: RecordGqlNode;
+  objectMetadataItem: ObjectMetadataItem;
+  toReference: ToReferenceFunction;
+};
+
+export const createCacheEdgeWithRecordRef = ({
+  record,
+  objectMetadataItem,
+  toReference,
+}: CreateCacheEdgeWithRecordRefParams): RecordGqlRefEdge | null => {
+  const reference = toReference(record);
+  if (!isDefined(reference)) {
+    return null;
+  }
+
+  return {
+    __typename: getEdgeTypename(objectMetadataItem.nameSingular),
+    node: reference,
+    cursor: encodeCursor(record),
+  };
+};