[bugfix] Revalidate with already-validated/proxied array

[sneakers-the-rat]

When a proxy object is passed to some validators after having already been validated, validation fails.

This should always succeed:

from numpydantic import NDArray
from pydantic import BaseModel

class MyModel(BaseModel):
    array: NDArray

instance = MyModel(array=valid_input)
_ = MyModel(array=instance.array)

but it's currently failing for the proxied interfaces.

This PR

• adds passthrough checks for h5proxy and videoproxy
• adds a testing module for tests against all interfaces, and tests that an already-instantiated model can be re-instantiated using the same array field after passing through the interface