Remove redundant/obsolete tests from intel_400x_tests.rs, retaining core test coverage for Intel400x common functionality. Apply rustfmt formatting to intel_4002.rs and state machine test files.
Changes:
- Remove ~40 redundant test functions from intel_400x_tests.rs
- Apply rustfmt formatting to intel_4002.rs
- Fix import formatting in state machine tests
- Clean up trailing whitespace
