Saving workspace functionality

Saving workspace functionality:
- the Dynamo receives a message about saving, saves all workspaces as files and sends them back to the Flood.
Part of changes that had to be uploaded with "Changing the way of geometry transmission" but wasn't:
- receiving a geometry message, process it and send back the geometry data
Enhancements of the code (there is not a lot of them, so I add them into this PR):
- checking for not null, correct guid, removing old code, etc
for some nodes their names (that is in the list of nodes) and what will be displayed on node itself are different. DisplayedName is name that will be displayed on node itself