Refactor: Simplify ErrorCode

[sehz]

The current Error Code needs to be refactored. The primary issue is that it strongly couples protocol to API-level error code. The error code references the error code in the higher-level components such as SC and SPU.

An updated error code version will only contain minimum error representation and downcast to a specific error code for each component. The changes need to be backward compatible until 0.11.0.