Split input label maps w metadata

[kaitj]

Tasks

• [x] Use nibabel to read labelmap
• [x] Add Python script to split labels into binary volumes
  • [x] Output as BIDS label masks
• [x] Fix dtype for memory purposes
• [x] Add in label descriptions from .tsv
• [x] Determine naming scheme
  • [x] Aggregation output rule

[jclauneuro]

As discussed there is an inherent limitation with appended (concatenated) volumes in c3D with 0..255 limit. Also just need to ensure that order of concatenation matches the expected label