Cellpose v4 parameters

[LouisK92]

A new set of hyper parameters was introduced with the v4 version of cellpose.

Find the details here. Note also that model_type and channels are deprecated.

• Define the grid search parameters for cellpose v4

In the txsim package I added an if clause that supports the v4 version: https://github.com/theislab/txsim/blob/main/txsim/preprocessing/_segmentation.py
Maybe we want to even support the previous models and call the v4 version "Cellpose-SAM", see the v4 paper here

[LouisK92]

Update: With 8015045 cellpose was downgraded to v3 as I couldn't manage to get cellpose-sam (v4) run in the time limit of the gh-actions tests