Replace 12 copy-pasted numeric field tests with 4 parametrized tests

Introduce a _create_entity helper and @pytest.mark.parametrize("entity_type",
["spool", "filament", "vendor"]) to run each numeric field type test against
all three entity types from a single test function.

- Removes 12 individual tests (integer/float/integer_range/float_range × 3 entities)
- Adds 4 parametrized tests covering the same ground plus the previously missing
  min-only / max-only range filter cases for filament and vendor
- Uses try/finally for cleanup so entities are always deleted even on assertion failure

Author: daften