Make error types more consistent

[MarquessV]

The way we define errors vary throughout the SDK. We sometimes define error types for specific calls, other times at the module level, and other times by pulling them in from elsewhere. While each approach can have its place, it doesn't appear to have been done with a lot of intent, and sometimes the Python module has differing error shapes from it's Rust counterpart. Many of our errors repeat themselves via thiserror (e.g. ExecutionError and executable::Error). We should have an agreed upon way we define errors that is consistent and intuitive across the SDK.