feat: introduce ciel-specific Python exceptions

[Gitjay11]

closes #131

Summary

This PR addresses issue #131 by introducing dedicated exception classes for ciel. Previously, ciel raised generic standard library exceptions (e.g., ValueError, RuntimeError, TypeError, IOError), forcing callers to catch broad exceptions and inadvertently capturing errors from third-party libraries or Python built-ins.

All new exception classes inherit from their corresponding standard library exceptions (ValueError, RuntimeError, TypeError, IOError) to ensure backward compatibility for callers catching base types while allowing fine-grained exception handling for ciel-specific errors.

Verification

• Confirmed all 10 new exception classes correctly inherit from their respective base classes.
• Verified top-level package imports (import ciel; ciel.InvalidPDKError, etc.).
• Ensured backward compatibility alias (VersionNotFound is VersionNotFoundError) functions as expected.