Activity timeline refactoring followup (#5835)

Following https://github.com/twentyhq/twenty/pull/5697, addressing
review

packages/twenty-front/src/utils/format/__tests__/formatDate.test.ts

@@ -0,0 +1,29 @@
+import {
+  formatToHumanReadableDay,
+  formatToHumanReadableMonth,
+  formatToHumanReadableTime,
+} from '../formatDate';
+
+describe('formatToHumanReadableMonth', () => {
+  it('should format the date to a human-readable month', () => {
+    const date = new Date('2022-01-01');
+    const result = formatToHumanReadableMonth(date);
+    expect(result).toBe('Jan');
+  });
+});
+
+describe('formatToHumanReadableDay', () => {
+  it('should format the date to a human-readable day', () => {
+    const date = new Date('2022-01-01');
+    const result = formatToHumanReadableDay(date);
+    expect(result).toBe('1');
+  });
+});
+
+describe('formatToHumanReadableTime', () => {
+  it('should format the date to a human-readable time', () => {
+    const date = new Date('2022-01-01T12:30:00');
+    const result = formatToHumanReadableTime(date);
+    expect(result).toBe('12:30 PM');
+  });
+});