Use DataTransfer instead of TransferFields on Install/Upgrade codeunits

[Arthurvdv]

The DataTransfer provides more control and possibilities then TransferFields.

DataTransfer is an AL data type that supports the bulk transferring of data between SQL based tables. Instead of operating on a row-by-row model, like the record API does, DataTransfer produces SQL code that operates on sets. This behavior improves the performance when moving data during upgrade and install.

codeunit 50100 MyCodeunit
{
    Subtype = Upgrade;

    trigger OnUpgradePerCompany()
    var
        OldTable: Record OldTable;
        NewTable: Record NewTable;
        TableDataTransfer: DataTransfer;
    begin
        TableDataTransfer.SetTables(Database::OldTable, Database::NewTable);
        TableDataTransfer.AddJoin(OldTable.FieldNo(Code), NewTable.FieldNo(Code));
        TableDataTransfer.AddFieldValue(OldTable.FieldNo(Code), NewTable.FieldNo(Code));
        TableDataTransfer.AddFieldValue(OldTable.FieldNo(Description), NewTable.FieldNo(Description));
        TableDataTransfer.CopyRows();
        Clear(TableDataTransfer);
    end;
}

So when a codeunit has the property Subtype = Install; or Subtype = Upgrade; then raise a diagnostic when a .TransferFields method is declared.