Cytoscape aspects should begin with "cy"

We now know that subnets are only interesting to Cytoscape, so subnet-related aspects should have "cy" as the aspect name prefix. The following should all have "cy" prefixes:

hiddenAttributes -> cyHiddenAttributes
subNetworks ->cySubNetworks
networkRelations -> cyNetworkRelations
visualProperties -> cyVisualProperties

The following _should_ already have cy prefixes:
cyViews
cyGroups

The following _should not_ have cy prefixes:
nodeAttributes
edgeAttributes
networkAttributes
cartesianCoordinates
edges
nodes

Locate the CX schema or Java serialization code that defines and uses hiddenAttributes, subNetworks, networkRelations, and visualProperties. Check those names alongside cyViews and cyGroups, then verify that only the four listed aspects gain the cy prefix while the explicitly excluded names remain unchanged.

Written by the indexing model from the issue text.