Get output from modular ingests before merge in Jenkins job

[glass-ships]

This PR adds a script to download the output of modular ingests from their releases
(listed in a dictionary with the format "ingest-name": ["output_file_nodes", "output_file_edges"] as applies to your ingest)'

As well as a step in the ingest-all Jenkinsfile to run this script right before the merge step.

A test run of this updated Jenkins job can be found here
(Note: this run failed because some modular ingests still have original_object as a column in their output, which causes cat-merge to fail)

@kevinschaper we should probably get @amc-corey-cox @madanucd and @AO33 access to Jenkins at some point.

Important Notes:

• ncbi-gene and alliance-variant-allele-ingest are currently commented out until we're sure they're ready to be included
• After merging this PR, we should re-point the Jenkins job to */main rather than this branch.

[glass-ships]

Possibly redundant, feel free to scrap