use tuple expansion if type._is_tuple, test for Sequence if no type

use tuple expansion if type._is_tuple, test for Sequence if no type

Fixed regression where the row objects returned for ORM queries, which are
now the normal :class:`_sql.Row` objects, would not be interpreted by the
:meth:`_sql.ColumnOperators.in_` operator as tuple values to be broken out
into individual bound parameters, and would instead pass them as single
values to the driver leading to failures. The change to the "expanding IN"
system now accommodates for the expression already being of type
:class:`.TupleType` and treats values accordingly if so. In the uncommon
case of using "tuple-in" with an untyped statement such as a textual
statement with no typing information, a tuple value is detected for values
that implement ``collections.abc.Sequence``, but that are not ``str`` or
``bytes``, as always when testing for ``Sequence``.

Added :class:`.TupleType` to the top level ``sqlalchemy`` import namespace.

Fixes: #7292
Change-Id: I8286387e3b3c3752b3bd4ae3560d4f31172acc22