Add lowmem parameter to MOFA

[wlason]

This solves #308

• Added lowmem option to batch_correct_mofa.py, which recalculates ATAC HVFs, keeping just top 25k
• Added lowmem to the integration YAML
• Fixed a bug where MOFA would error if filter_by_hvg in YAML is set to anything other than True (filter_by_hvg was erroneously passed to mu.tl.mofa kwargs)

[wlason]

I think as additional improvements it would be worth to print number of features in every mod used by MOFA in the logging info - easier to troubleshoot

[bio-la]

@wlason this seems to work fine, i would just like you to add a new CI to test the lowmem parameter for MOFA.
Can you please check the integration actions we are running with the respective pipeline.yml and create a new one? you can simply create a copy the action and the pipeline ymls, giving them a different name, and edit the relevant MOFA sections in the yaml. happy to help!