fdo#82151 when constructing column object, replace m_aCurrentRow by a function

The passed m_aCurrentRow becomes out-of-date as soon as the current row changes.
This also hides an implementation detail of ORowSet to ORowSet(Data)Column.

Change-Id: Ib9188743e5dd6dec240e9f5fd3fd9655c6761abc
Reviewed-on: https://gerrit.libreoffice.org/10792
Reviewed-by: Lionel Elie Mamane <lionel@mamane.lu>
Tested-by: Lionel Elie Mamane <lionel@mamane.lu>