Ensure bindparam key escaping applied in all cases

Ensure bindparam key escaping applied in all cases

Fixed regression where the :class:`_sql.BindParameter` object would not
properly render for an IN expression (i.e. using the "post compile" feature
in 1.4) if the object were copied from either an internal cloning
operation, or from a pickle operation, and the parameter name contained
spaces or other special characters.

Fixes: #6249
Change-Id: Icd0d4096c8fa4eb1a1d4c20f8a96d8b1ae439f0a