Identify and separate unit and integration tests in other packages

[masci]

Follow up of Revisit unit and integration tests

These tasks might include partial refactoring of the existing testing workflow.

• Modeling -> most of them are end-to-end
• Pipeline -> many unit tests, a few end-to-end, no integration
• Nodes -> Very varied, probably best to tackle last

Note: many nodes and modeling tests can make use of hf-internal-testing models to limit the size of models being tested, reduce the memory footprint, improve speed etc.