test(napi): add coverage tests for data types and object operations (#32962)
## Summary
Adds NAPI test coverage for data types and object operations that were
previously untested or undertested.
### Data Types (new + extended)
- **Buffer** (new): `napi_create_buffer`, `napi_create_buffer_copy`,
`napi_get_buffer_info`, `napi_is_buffer`
- **DataView** (new): `napi_create_dataview`, `napi_get_dataview_info`,
`napi_is_dataview`
- **Numbers** (extended): `napi_create_double/get_value_double`,
`napi_create_uint32/get_value_uint32`
- **Strings** (extended):
`napi_create_string_latin1/get_value_string_latin1`,
`napi_create_string_utf16/get_value_string_utf16`
### Object Operations (extended)
- `napi_get_property_names`, `napi_get_all_property_names`
- `napi_has_property`, `napi_has_own_property`,
`napi_has_named_property`
- `napi_delete_property`
- `napi_has_element`, `napi_delete_element`
- `napi_object_freeze`, `napi_object_seal`
- `napi_get_prototype`
- `napi_strict_equals`
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Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>