MILESTONE: Match C++ engine in octopus

[blairlyons]

• [x] https://github.com/simularium/octopus/issues/5
• [x] https://github.com/simularium/octopus/issues/12
• [x] https://github.com/simularium/octopus/issues/29
• [x] https://github.com/simularium/octopus/issues/43
• [x] https://github.com/simularium/octopus/issues/39
• [x] https://github.com/simularium/octopus/issues/38
• [x] https://github.com/simularium/simulariumio/issues/151
• [x] https://github.com/simularium/octopus/issues/40
• [x] https://github.com/simularium/octopus/issues/44
• [x] https://github.com/simularium/octopus/issues/45
• [ ] https://github.com/simularium/octopus/issues/11
• [ ] https://github.com/simularium/octopus/issues/49
• [x] https://github.com/simularium/octopus/issues/50

Use Case

As a developer of the viewer, I want the octopus engine to have all the features I required from the current C++ engine so that it can be used in production with the viewer.

Acceptance Criteria

All the current requests made by the viewer to the C++ backend can be handled by octopus reasonably performantly.

[toloudis]

A couple of other things to check:

• need to implement secure websockets wss protocol?
• chunked binary messages
• automate deployment via gh-actions? - might be much simpler than simularium-engine if we leave out all the k8s stuff and just go straight to an instance
• stress test in staging in cloud
• have we covered all the websocket messages that the viewer wants to send/receive?

[blairlyons]

@ascibisz also think about other features needed to bring Octopus to parity with C++ engine