UI UX improvements

[kegsay]

When viewing large graphs, it's hard to track which node is which event due to the descriptors being off the edge on the right due to the graph being so bushy.

Perhaps:

• on hover => tooltip with the information
• on click => keep the event highlighted along with its edges, and keep the tooltip active.

This would allow users to "select" arbitrary events and see the edges / event information. Bonus points to highlight edges between selected events e.g reachability queries.

Likewise, viewing the raw JSON is cumbersome as you need to find it on the left-hand list. Perhaps a new window to show event JSON of selected events?