Revisit anatomical suffix filtering

[jpillai00]

Currently, anatomical input filtering is set to T1w only:

for _, anat_df in session.anat.filter(pl.col("suffix") == "T1w").group_by(
         _ANAT_GROUP_ENTITIES, maintain_order=True
):

We should revisit this to determine how/whether other anatomical suffixes (e.g. T2w, FLAIR, etc.) should be supported.

[kaitj]

Other thing to note is this is currently done across a few workflows. Could also look into setting this in the load_session function.