Add Approval Date to Timesheets and Assignments

Enable queries to filter data by the approval date of timesheets or assignments. This feature would be particularly useful for overtime reporting, allowing integration with external payroll providers based solely on approved data, regardless of when the work was conducted, rather than limiting by period (e.g., last month). It would remove the amount of manual intervention by the HR and payroll team, including reminding managers to process requests or missing any overtime requests, all due to the limited filtering options.