ImplicitOutputShape is not properly validated?!

[constantinpape]

We specify that shape = shape(input_tensor) * scale + 2 * offset for the ImplicitOutputShape, see https://github.com/bioimage-io/spec-bioimage-io/blob/gh-pages/model_spec_latest.md.
However, it seems like this is not properly checked in bioiamgeio test-model:
test-model passes for https://github.com/bioimage-io/spec-bioimage-io/blob/main/example_specs/models/stardist_example_model/rdf.yaml#L39; however, the correct value would be 33 / 2.
@FynnBe we should make sure that the ImplicitOutputShape (and also InputShape etc.) are validated for the test input / outputs.
Is test-model the best place to do this or can we do it even earlier in validation?

[FynnBe]

after "offline" discussion:
in bioimageio validate we do not test if the specified files even exist. For simplicity we should keep it that way, which avoids any trouble running the validate command in pyodide, etc.
Therefore I will add the check for shape matching of test data and description to bioimageio test-model here in core.

[FynnBe]

in the docs we do not specify how we round the shape(input_tensor) * scale part? numpy.round_() to dodge the specifics on our side?