Daemon: License cache

The daemon needs to function in pure offline scenarios and in cases where the network connection has dropped temporarily.

This means that the Daemon needs to cache the licenses locally.

The same cache should also support a run-time cache to avoid unnecessary calls to the server, e.g. in the floating-license model.

We also must support that the users download the license(s) manually from Customer Portal and saves the license(s) to pre-defined folder where the Daemon can find those.