When the `tax-per-item` is enabled and also has a tax added, during the
item creation, the price + tax returns an amount as float making the
database fail. To fix this was necessary to round the result.
* Possibility to set a fixed amount on tax types settings
* Pint and manage flat taxes on items
* Fix display errors and handle global taxes
* Tests
* Pint with PHP 8.2 cause with PHP 8.3 version it cause workflow error
* Merging percent and fixed amount into one column
* Now display the currency on SelectTaxPopup on fixed taxes
