The BulkWriteResult class has a public property called `result` which contains the raw bulkWrite response.  The class also has getters which just reach into the `result` object to pass nested properties out.

This causes issues with the unified test suite runner for `rewrapManyDataKey` operations because our BulkWriteResult class has extra properties (the `result` property), causing tests to fail.  We worked around this in the test runner by making the property non-enumerable before returning it from the operation handler, but this is not ideal.

Acceptance Criteria

• Refactor the BulkWriteResult class to set each property in the constructor instead of using getters.