Add Array instance test

[kamoii]

Description of the change

Adds few test for Array instances. Since these instance are implemented by ffi, tests would be usefull for testing alternative backends.

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Checklist:

• [ ] Added the change to the changelog's "Unreleased" section with a reference to this PR (e.g. "- Made a change (#0000)")
• [ ] Linked any existing issues or proposals that this pull request should close
• [ ] Updated or added relevant documentation
• [ ] Added a test for the contribution (if applicable)

[kamoii]

Added test for Record.Unsafe too.