Migrate Entity Extraction Filters, Part II.b

This is a follow-up of !2665 (merged) and depends/includes that MR.

Addresses #601 (closed) and https://gitlab.kitware.com/kmorel/ecp-vtk-m-project-management/-/issues/328.

This MR is actually a painstaking rebase of !2668 (closed), which got its history trashed.