[Fixes #14136] Fixes the support for creation of dataset with generic Geometry type

[sijandh35]

Fixes #14136

Checklist

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[gemini-code-assist]

Code Review

This pull request implements support for generic 'Geometry' types within vector handlers and empty dataset utilities, mapping them to Django's GeometryField and GeoServer's JTS Geometry binding. It also updates the setup_dynamic_model method to support layer names provided as strings. A review comment suggests updating the type hint for the layer parameter in setup_dynamic_model to include str for better type safety and clarity.