Bulk import fixes

[annaCPR]

Description

• do not look up counter if import_id already provided when saving events or documents
• add default value of none to user_language_name on IngestDocumentDto
• validate that a family exists before saving an event

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Reviewer Checklist

• DB_CLIENT DEPENDENCY IS ON THE LATEST VERSION
• The PR represents a single feature (small drive-by fixes are also ok)
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[katybaulch]

Good work - can we pull any of the repeated code behaviour into it's own helper function?

[katybaulch]

lgtm, nothing blocking