[Go] Fix "allOf" inherited model properties by embedding parent models

Created by: DouglasDwyer

This PR addresses issue #10219. The Go client generator does not include properties from allOf dependencies in generated models. This is solved by embedding the parent models into the generated Go structs, making all properties (including inherited ones) available on models. This behavior also more closely matches the Swagger API generator, which handles allOf cases like this by including all of the inherited properties (including parent properties) in the generated models.

PR checklist

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  ./mvnw clean package 
  ./bin/generate-samples.sh
  ./bin/utils/export_docs_generators.sh

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