Longitudinal qc_metrics

[eroell]

Description of feature

This is a function that operates on .X or .layers so 3D and array-type and encoding is relevant.

3D
If 3D allowed:

• function handles 3D data
• the test of the function tests both the expected 2D and 3D implementation

If 3D not allowed:

• only_2D decorator
• the test of the function tests for failure if 3D is passe

array-type
The available array types are np.array, dask.array, and scipy.sparse matrices.

• function is single-dispatched, with potential not_implemented errors being raised
• test is parametrized to test the different array-types

Encoding
If encoded data is required

• mention in documentation that encoded data is needed, with ep.pp.encode.

[Zethson]

I am generally not sure whether our QC function is any good. We might want to ask some LLMs for ideas to improve it first before simply enabling 3D etc.