streamline and document controller public API

## What needs to happen?

- [ ] consolidate duplicate code paths (clearFile, cancelCurrentFile)
- [ ] remove unused code paths (postConnect, initializeTrajectoryFile)
- [ ] move ownership of variables/abstractions into appropriate subclasses (websocketClient)
- [ ] document public API methods
- [ ] organize methods by category


## Why should we do this?



## When does this need to get done?
