Raw AES Keyring zeros out passed in unwrappedMasterKey

### Problem:

The materials manager zeros out the dataKey in the processing of creating wrapping key material during construction:
https://github.com/aws/aws-encryption-sdk-javascript/blob/6b1d1a6cd62d56dfb47eb9b70307b5f9083e5e10/modules/material-management/src/cryptographic_material.ts#L823-L838

This is normally good practice. However in the case where the buffer has been passed in by the customer via Keyring creation, for example in the Raw AES Keyring case, this leads to surprising behavior.

The Raw AES Keyrings does not make a defensive copy of the key material before creating this material: https://github.com/aws/aws-encryption-sdk-javascript/blob/master/modules/raw-aes-keyring-node/src/raw_aes_keyring_node.ts#L63

And thus the "unwrappedMasterKey" that the customer passed in looks like it gets "consumed." This is surprising to the customer, especially since our docs have no indication of this behavior.

### Solution:

The Raw AES Keyring should make a defensive copy of the "unwrappedMasterKey" in it's constructor. It is the responsibility of the customer to zero out the "unwrappedMasterKey" in their application after creation of the Keyring if it is no longer needed, in order to minimize the time the data key exists in plaintext in memory.

### Out of scope:

Is there anything the solution will intentionally NOT address?

[//]: # (NOTE: If you believe this might be a security issue, please email aws-security@amazon.com instead of creating a GitHub issue. For more details, see the AWS Vulnerability Reporting Guide: https://aws.amazon.com/security/vulnerability-reporting/ )

Đọc mã của trình quản lý vật liệu trong modules/material-management/src/cryptographic_material.ts quanh các dòng 823-838, sau đó kiểm tra hàm khởi tạo của Raw AES keyring trong modules/raw-aes-keyring-node/src/raw_aes_keyring_node.ts quanh dòng 63. Xác nhận rằng hàm khởi tạo tạo một bản sao phòng thủ của unwrappedMasterKey do khách hàng cung cấp để việc xử lý vật liệu sau đó không ghi số 0 vào buffer của bên gọi.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.