Create a library to abstract the handling of all configurations on Signstar hosts

Currently we only have system-wide Signstar configuration support which allows us to create system users based on this.

To allow the creation of NetHSM users in the backend, we need a central library that allows us to create and gather data relevant for these users. This involves the handling of dedicated configurations for administrative accounts and passphrases as well as passphrases for non-administrative users on the NetHSM backend.