Add with_for_update() support in session.refresh()

Add with_for_update() support in session.refresh()

Session.refresh() is still hardcoded to legacy lockmode,
come up with a new API so that the newer argument style
works with it.

Added new argument :paramref:`.with_for_update` to the
:meth:`.Session.refresh` method.  When the :meth:`.Query.with_lockmode`
method were deprecated in favor of :meth:`.Query.with_for_update`,
the :meth:`.Session.refresh` method was never updated to reflect
the new option.

Change-Id: Ia02a653746b7024699b515451525a88d7a17d63a
Fixes: #3991