Decryption key:
Add setting currency rates
Allows creating payslips by currency
Update screens and functions related to currency in payslip: payslip in employee details, payslip pdf, payslip report
Fix bug: add remove column when editing Payslip Template.
Payslip download ZIP, fix error of employee without an Employee ID number when exporting pay slip, no pay slip PDF file will be created
Upgrade source code to be compatible with PHP 8.1.
Upgraded features to be compatible with the latest version of Perfex CRM.
