Feature Request: Support invoicing daily (flat-)rates based on Task logs

Feature Request: Support invoicing daily (flat-)rates based on Task logs: Right now the rate in InvoiceNinja is always set to hourly. In my field of work it's quite common that freelancers usually work for a fixed daily rate and invoice the full day if they worked for example ~6-8 hours a day or a half day if they worked less than 6 hours etc.. Right now there's no proper way to cover this case properly in InvoiceNinja. The only workaround I have right now is to create a Product for a daily rate and then calculate the total days (manually)...