[clbarnes]

This PR ports most of the test cases from ome_zarr_transformations_conformance for validating the numerical accuracy of transforms.

Differences from oztc

• Replace test-specific conformance.toml with oztest.json, with the plan for this to be extended per Allow for descriptions in test cases #46.
• Put tests into the same hierarchy structure as the other test case kinds, so that they can use the same discovery mechanisms. This means they all exist under the valid validity but I'm OK with that
• should_error = true cases, previously only used for disconnected transform graphs, were not ported. These are better tested by the validate_zarr cases.

To do

• byDimension_nonContiguous cases would belong to more than one profile; they should be simplified to only use core transforms
• coordinates/ displacements need updating to use a multiscale
  • should we test different interpolation types?
• projectAxis test cases