Support domain type interface as return type

[gastonlagaf]

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Related to issue https://github.com/spring-projects/spring-data-cassandra/issues/1335

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[mp911de]

Using a slightly different scheme to determine the domain type, see https://github.com/spring-projects/spring-data-cassandra/commit/515bffc784c19f1c67607162043e1f63397b523b.