[rust][reqwest] support binary type for download

[ThomasVille]

fix #18117

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[ThomasVille]

I created a PR with the same code as #18682 to see which tests are failing in the CI.

[ThomasVille]

The CI needs approval to run, but I can run the tests locally.

[DDtKey]

Let's update the branch and mark the PR as ready for review?

I've described my opinion in the issue: #18117 (comment)

[wing328]

@DDtKey thanks for the feedback.

Did you test the change locally? e.g.

git checkout -b ThomasVille-rust_binary_type_support master
git pull https://github.com/ThomasVille/openapi-generator.git rust_binary_type_support

and the build the CLI JAR by running mvn clean package (or using maven wrapper included in this repo)

[ThomasVille]

@wing328 I ran these commands:

git clone [email protected]:OpenAPITools/openapi-generator.git
cd openapi-generator/
git checkout -b ThomasVille-rust_binary_type_support master
git pull https://github.com/ThomasVille/openapi-generator.git rust_binary_type_support
./mvnw clean package

And here is the result clean-run.txt.

It looks like everything succeeded.

So I synced my fork with the upstream repo and rebased my branch on master. So the PR should now contain the latest changes from master.

[wing328]

@ThomasVille thanks for the info.

Can you please add a fake endpoint in the petstore test spec to test binary return type?

test spec: modules/openapi-generator/src/test/resources/3_0/rust/petstore.yaml

an example of fake endpoint in other test spec: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml#L1227-L1267

then regenerate the samples to ensure the changes are good