Deduplicate block setattr logging helpers

[wshlavacek]

Summary

• factor repeated block __setattr__ logging paths into shared helpers in the model and network block modules
• unify logger-backed warnings for invalid non-coercible assignments across the remaining block subclasses
• route duplicate action-argument warnings through BNGLogger and fold the duplicate OrderedDict import-guard cleanup into the same refactor
• add focused upstream-safe regression tests for the setattr/logging paths

Testing

• uv run pytest tests/test_block_setattr_logging.py -q
• uv run pytest tests/test_bionetgen.py::test_bionetgen_model tests/test_bionetgen.py::test_action_loading tests/test_bng_parsing.py::test_network_parse -q
• uvx black --check bionetgen/modelapi/blocks.py bionetgen/network/blocks.py bionetgen/modelapi/structs.py tests/test_block_setattr_logging.py

[jrfaeder]

@wshlavacek Please check the conficts

[wshlavacek]

@jrfaeder conflicts resolved and the branch has been rebased onto current main. The focused block setattr logging tests pass locally, so it should be ready for another look.

[wshlavacek]

CI root cause looks narrower than the PR UI suggests: I do not currently see a live merge conflict, but I do see a reproducible warning-message regression causing the full deploy matrix to fail.

The helper dedup changed parameter and compartment warning text from the existing field-specific wording ("keeping existing value" / "keeping existing size") to generic wording ("keeping existing parameter" / "keeping existing compartment"). Upstream tests in tests/test_block_warning_paths.py still assert the older wording, so we now fail the same four assertions across every platform. I reproduced those four failures locally as well.

Tentative fix plan:

1. Preserve the existing field-specific warning wording for parameter and compartment numeric-assignment failures in both model and network block helpers.
2. Update tests/test_block_setattr_logging.py so the new focused tests match the established upstream warning contract instead of the regressed generic wording.
3. Re-run the focused warning-path and block-setattr tests locally, then force-push the repair branch.

I am keeping this PR in draft until that repair is in.