Extend --convert-tensor-to-scalars beyond tensor.insert/extract

[AlexanderViand-Intel]

The --convert-tensor-to-scalars pass introduced in PR #763 currently only handles tensor.insert and tensor.extract operations, but not other similar tensor operations, such as tensor.slice.

As part of this, it'd be a good idea to extend the tests for this pass beyond the tests generated from HEIR's polynomial-pipeline to a wider range of general tensor use cases. (Especially since we might want to suggest #524 and this pass for inclusion upstream at some point),

(labelling as tensor_ext, as it's tensor-related, even though this is technically a transform for "raw" tensor ops rather than tensor_ext ops)