What problem are you facing?

Error handling in change streams relies on the error codes that are return in MongoSystemError objects.  The current constructor of MongoSystemErrors is structured in such a way that the error code is stored in an object on the error and not as a top level property.  This means that error handling code does not have access to the error code and for change streams.

Acceptance Criteria

• Store the `code` on the MongoSystemError as a top level property

Potential Additional Acceptance Criteria

• Many errors do not have tests associated with them.  Convert the error.test.js tests to Typescript and add tests for any missing errors.
• There may be other errors that should propagate the `code` key as well.  We could fix any errors that have a `code` as a part of this ticket.