Folder: Allow to create temp_objects anywhere, without checking if it's in allowed types for that Portal Type.

Until now, creating a temp_object with newContent() required for the temp_object
to be in allowed types. However, this was inconsistent with (now deprecated)
newTemp*() functions (calling directly constructInstance()) not having such
limitations.

Besides lifting such limitation being needed to properly replace newTemp*() calls,
portal_trash.newContent() pattern is already commonly used used here meaning there
is a real use case.

This also fixes testBanking* failures: newTempCashDeliveryLine() created objects
on 'Cash Inventory' and latter call Delivery.isAccountable() which does not exist on
portal_trash.

See also 04b49859.

/reviewed-on !1025