Add error handling conventions

[janhalama]

Description

This PR adds error handling conventions.

Motivation and Context

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [ ] I have read the CONTRIBUTING document.
• [ ] I haven't repeated the code. (DRY)
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.

[janhalama]

@tmladek thank you for your suggestions 🙏 and language fixes

[janhalama]

The error handling conventions are obsolete with the new WASM OneSDK.