* Refactor string usage for secrets (#394)
Strings are immutable and the lifetime of secrets can not be controlled.
Use byte[] or char[] instead of strings for secrets, which can be erased
after use.
* Clear pw
---------
Co-authored-by: Martin Regen <7962757+mregen@users.noreply.github.com>
-Implement the support for ApplicationSelfAdmin privilege
-implement the workflow in a test to pull the trust list after sucessfully receiving a gds signed certificate.
-this authorization is described here in the OPC Spec: https://reference.opcfoundation.org/GDS/v105/docs/7.6
- move IUserDatabase + RoleBased Identity into standard Server
- subclass SystemConfigurationIdentity from RoleBased Identity for backward compatibility
- add OPC UA Spec Defined Roles to the RoleBasedIdentity