Fix swapping items client data in wxEditableListBox.

Use wxUIntPtr, not long, and SetItemPtrData() instead of SetItemData(), to
ensure that we preserve the values of client data pointers in 64 bit build,
otherwise they were truncated to 32 bits.

Closes #15687.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@75247 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775