[master] add a step splitter by input filetype and pydantic modernisations / squashing of warnings
cc @cburr
BEGINRELEASENOTES
*ProductionManagementSystem NEW: support multiple input filetypes in local tests.
*Core FIX: fix warnings in BookkeepingJobInfo model and BookkeepingReport module by simply casting to string before assigning fields.
ENDRELEASENOTES
Edited by Ryunosuke O'Neil