Created a "IsValidCPR" method that checks the format and date of a
string. To close the issue entirely, this check should be used in
"DoneButtonClick" method and a proper error message should be displayed
to the user should the inputted CPR number have an invalid format.
This issue is unfortunately no longer necessary as the Population Register does not supply the voter list with CPR numbers and thus it cannot be used to register or validate voters.
Created a "IsValidCPR" method that checks the format and date of a string. To close the issue entirely, this check should be used in "DoneButtonClick" method and a proper error message should be displayed to the user should the inputted CPR number have an invalid format.