Cases uncaught from validation for raster data

[LucaMarconato]

The xarray.DataArray constructed here https://github.com/single-cell-data/TileDB-SOMA/blob/fe8e64d88173b0d79d93893a778eb481a75ff2c5/apis/python/src/tiledbsoma/io/spatial/outgest.py#L309 creates a object that passes our validation but that differs from the same object after a call of the parser in the .indices and .coords.

We should ensure that the validation is not passed when those variables are not set. I suspect the problem appears also for multiscale images.

• [ ] test for mutliscale images as well.