convert SvStream::operator>> methods to ReadXXX methods

First, I updated the clang rewriter to do the conversion.
Then I lightly hand-tweaked the output for the few places where
the rewriter messed up, mostly when dealing with calls on "this".

Change-Id: I40a6a977959cd97415c678eafc8507de8aa3b1a9
Reviewed-on: https://gerrit.libreoffice.org/7879
Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Michael Stahl <mstahl@redhat.com>