todo: provide a way for sample distributions to validate truth space #55
Description
In some cases, the ground truth renderer may not accept all possible truth spacings. For example, in the cosem renderer in #18, it is currently only designed to work with truth space spacings of 4nm (since that's what the janelia dataset is based on). Of course, that's something that could (and should) be fixed in the Cosem renderer, using interpolation or whatever means it needs to to be compatible with any arbitrary space request... however, until then it seems reasonable that it should be able to say "can't accommodate that yet", and that should happen immediately upon creation of a Simulation object (and not have to wait until render is called).
So, I proposed adding something like a .supports_truth_space() classmethod to distribution objects, which will be used during model validation of the Simulation object, allowing them to fail early and informatively