Match on ncs- in installer filename too

The way we used to compute the filename of the installer (if the input to us was just an NSO version) we used to assume the NSO version went in between a few predefining characters that started with 'nso-'. However, it appears that most normal NSO releases start with nso- in the filename while nightly builds are still called ncs-x.y.z.a.. To cater to this, we modify the matching of filenames so we now also are able to match on ncs- filenames.

Part of #115 (closed)