Add API method to calculate total leave applied and approved (Leave Taken)
Leave Entitlement disable Input into Taken Leave and Balance Leave
When add new Leave Entitlement, Taken Leave is set to 0, Balance Leave = Available Leave
When edit existing Leave Entitlement, Taken Leave is validated against Calculated Leave from Applied Leave API, Balance Leave = Available Leave - Taken Leave
Adjusted Leave Entitlement page layout, resize numeric fields, and added field for validation message
Fix issue with Public Holiday react table not being refresh after adding new public holiday
Changes for #154 , #163 , #186