convert SvStream::operator<< overloads to more explicit methods

This is in preparation for more conversion of SvStream::operator<< calls
to use more explicit method names.
This converts the subclasses that have their own convenience overloads
of operator<< to use normal methods.

Change-Id: I5efd5d9a24c264cb86d2471303dd5849bf91ba80
fdo#73043: sw: fix Index/TOC Assign Styles dialog

SvTabListBox::GetEntryText(pEntry, 0xffff) will append 10 tabs to the
returned string, so it will no longer be equal to a style name.

(regression from 77173d8954c370bcaca80b48181c330b759b9517)

Change-Id: I7d3bee47eabec9180d6352fb6cf1b2e948153d37
sw: the Assign Styles dialog is not called Insert Database Columns

Change-Id: I96e0ee5fa0c7e45989cee663378d2ea7516fddfe