Return Error Types for API calls

[jazzz]

Core API functions ought to have consistent method to return errors to developers code. Currently some functions return errors, and others do not.

Considerations:

• This will require C-bindings to be updated
• UX impacts. What is the most ergonomic way to pass errors across the FFI to C?

[jazzz]

@osmaczko putting this on your radar. Not critical now, however if its a blocker for bindings let me know and I can prioritize that.