Qnx: Handle bbnk-env file extension when adding manual target

Task-number: QTCREATORBUG-10745

Change-Id: Ibefc228699ee339adccef5126cc167575be3ba5e
Reviewed-by: David Kaspar <dkaspar@blackberry.com>
Reviewed-by: Tobias Nätterlund <tobias.naetterlund@kdab.com>
Reviewed-by: Nicolas Arnaud-Cormos <nicolas@kdab.com>
Qnx: Fix displayed information for BlackBerry configs

* Update the target's information list when selecting
a manual configuration.

* Fix the target's name on Windows
as QNX_TARGET value uses Unix-like separator.

Task-number: QTCREATORBUG-10600

Change-Id: If1cd5ec2457c9f59f0290a74dd71fa4ffd0d73df
Reviewed-by: David Kaspar <dkaspar@blackberry.com>
Reviewed-by: Tobias Nätterlund <tobias.naetterlund@kdab.com>
Reviewed-by: Nicolas Arnaud-Cormos <nicolas@kdab.com>