The rust generator should support dropping the generated code into an arbitrary path in the crate. Currently, each generated file refers to the absolute path crate::models, forcing the use of hacks like search and replace if the generated could should be in crate::api::models, for example.

We can generate with use super::super::models instead.

This shouldn't break anything since if the module is at crate::models, super::super will also refer to the crate root.

Closes #20740

PR checklist

• Read the contribution guidelines.
• Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• Run the following to build the project and update samples:

  ./mvnw clean package || exit
  ./bin/generate-samples.sh ./bin/configs/*.yaml || exit
  ./bin/utils/export_docs_generators.sh || exit
  

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  Commit all changed files.
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  • @frol (2017/07) @farcaller (2017/08) @richardwhiuk (2019/07) @paladinzh (2020/05) @jacob-pro (2022/10)