RDBC-1029/1030 Fix bulk insert error detection and Enum dict key serialisation

[redknightlois]

Issue link

https://issues.hibernatingrhinos.com/issue/RDBC-1029
https://issues.hibernatingrhinos.com/issue/RDBC-1030

Additional description

RDBC-1029 – BulkInsert._get_exception_from_operation called the non-existent str.starts_with method (Python has str.startswith), raising AttributeError on any bulk-insert server error. Fixed the typo.

RDBC-1030 – Utils.entity_to_dict passed a dict with Enum keys directly to json.dumps, which raises TypeError because Enum instances are not JSON-serialisable as keys. Fixed by recursively normalising Enum keys to their .value before serialisation.

Type of change

• Bug fix
• Regression bug fix
• Optimization
• New feature

How risky is the change?

• Low
• Moderate
• High
• Not relevant

Backward compatibility

• Non breaking change
• Ensured. Please explain how has it been implemented?
• Breaking change
• Not relevant

Is it platform specific issue?

• Yes. Please list the affected platforms.
• No

Documentation update

• This change requires a documentation update. Please mark the issue on YouTrack using Documentation Required tag.
• No documentation update is needed

Testing by Contributor

• Tests have been added that prove the fix is effective or that the feature works
• Internal classes added to the test class (e.g. entity or index definition classes) have the lowest possible access modifier (preferable private)
• It has been verified by manual testing
• Existing tests verify the correct behavior

Testing by RavenDB QA team

• This change requires a special QA testing due to possible performance or resources usage implications (CPU, memory, IO). Please mark the issue on YouTrack using QA Required tag.
• No special testing by RavenDB QA team is needed

Is there any existing behavior change of other features due to this change?

• Yes. Please list the affected features/subsystems and provide appropriate explanation
• No

UI work

• It requires further work in the Studio. Please mark the issue on YouTrack using Studio Required tag.
• No UI work is needed