SfxPoolItem has a copy constructor and its copy assignment
operator is deleted. Derived classes have a implicit defined
copy constructor too, if all members are copy constructible.

This patch removes default-able copy constructors and destructors
on such items.

Also removing copy constructors of pool item members
SvxClipboardFormatItem_Impl and SvxColumnItem.

Change-Id: Ic0f39c992d1fd7b667cb56134fd7c953681a3131
Reviewed-on: https://gerrit.libreoffice.org/43143Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>