Track deserialization exception type for targeted handling

[bjester]

Overview

Complexity: Low
Target branch: release-0.8.x

Context

When a deserialization error occurs, Morango stores the error message on the Store record in the deserialization_error field.

The Change

It would be convenient if Morango had another field, perhaps deserialization_exception, which provides the fully-qualified exception module path of the error that occurred during deserialization. The deserialization_error would continue to be a string message of the error. The new field would allow more programmatic handling of these errors, and avoid parsing the error message.

Acceptance Criteria

• A new deserialization_exception field should be added to Store
• Migrations should exist for this change
• The deserialization process should store the full exception module path whenever it currently sets deserialization_error
• Tests should cover this change

Out of Scope

Handling specific errors

References

Followup to #306

[bjester]

Closed by #316