Remove old graphql functions and add last_opened/last_updated onto graph

[miratepuffin]

Once we have ported the UI saving over to the new more generic APIs we need to remove the following funcitons:

• [ ] update_grpah
• [ ] create_graph
• [x] update_graph_last_opened (should be done via new functions below)
• [x] archive_graph (can be done by updating consant properties)

We then need to add the following function onto GQLGraphs and GQLGraph:

• [x] last_updated
• [x] last_opened