Write results to cwl.output.json to bypass size restrictions

This MR modifies the way LINC collects the output in the filter_ms_group step. The output is written to cwl.output.json, which is then parsed as part of the collection of the outputs. This the loadContents field to circumvent size restrictions.

Solves #63 (closed).

steps/filter_ms_group.cwl

@@ -31,7 +31,6 @@ outputs:
 label: filter_ms_group
 
 requirements:
-#  - class: InlineJavascriptRequirement
   - class: InitialWorkDirRequirement
     listing:
      - entryname: filter_ms_group.py