REACH-29 Save workspace into client file system

In the Flood we can save home workspace and custom node workspaces as files. And later we can restore this workspaces from files.
Save: the Dynamo receives a message about saving, saves all workspaces as files and sends them back to the Flood.
Upload: the Dyname receives a file as byte array, saves them as a file, upload this file, sends all needed for restoring the workspace data to the Flood
It occurs when there remained custom nodes loaded during a previous session. I'm going to add clearing workspace and custom nodes when new session is connected. And then I'll delete this changes because this case will become impossible :)