switch to newer arroyo format, add pixi

[dylanmcreynolds]

This does several things:

• Adds pixi platform for development builds
• Switches to the newer arroyopy "block" configuration format
• Switching to blocks required adding factory methods for some of the arroyo classes
• Removes viz-operators (for now)
• Removes unused cli modules
• massive linting
• massive unit testing
• copies code out of the mlex_latent_explorer project for eventual deletion over there

Also, this fundamentally changes how many units are needed. In the past, a single unit listened to tiled, then sent frame over zmq pub. This let multiple zmq subs efficiently get the frames from one source. But this gets really tricky for configuration. For the sake of simplicity, this has been removed.

This means that we also removed several simulator apps. Now, the go-to simulator app is arroyosas.app.tiled_event_sim_cli which reads files and publishes over websockets like tiled would.