Filebrowser: Remove Saved Connections from Backend #185

Connections are currently saved in the backend but should be saved only by the frontend as to not be accessible to an invader that has gained access to the cluster. While it's still insecure by being saved inside the user's browser without further security measures, it's the better alternative. In the future, the best course of action is to move these connection details to a user database inside the cluster which securely communicates those details. But at the moment, we do not have a database for this to work. As such, we're saving the details inside of the browser!