cxx/satellite: don't drop unused config keys!

initializing is the only place where we can edit the config and e.g. add default values for settings.

If they are to be used later instead of directly (e.g. in launching) they are currently stripped away from the config and never reach anywhere outside initializing. I don't think this is particularly useful because it would mean reading all config parameters in initializing and storing them in some class members.

I am also contemplating removing the WARNING message for unused keys from the store_config - because at least from my perspective, it is not expected that at this time, all config keys should have been used.

Maybe even going one step further, providing a const Configuration& as parameter to launching() would even be helpful?

SOme discussion points here. 😄