fix(NODE-7414): add copy method to ByteUtils

[PavelSafronov]

Description

Summary of Changes

Add copy method to ByteUtils, with web and Node implementations.

What is the motivation for this change?

Add a common copy method which will be used by Node Driver

Release Highlight

Buffer.copy() now present in ByteUtils

ByteUtils now contains a copy() method, we behaves identically to Nodejs' Buffer.copy() method.

Double check the following

• Lint is passing (npm run check:lint)
• Self-review completed using the steps outlined here
• PR title follows the correct format: type(NODE-xxxx)[!]: description
  • Example: feat(NODE-1234)!: rewriting everything in coffeescript
• Changes are covered by tests
• New TODOs have a related JIRA ticket

[addaleax]

Does this need a separate implementation for Node.js? Always using the web one would result in consistent validation and otherwise no major downsides, right?

[PavelSafronov]

Does this need a separate implementation for Node.js? Always using the web one would result in consistent validation and otherwise no major downsides, right?

We can use the web implementation in both cases, but I don't think we should. Other operations in ‎src/utils/node_byte_utils.ts‎ use Buffer.* methods, like the below implementation of concat, and I think we want to keep this approach, in part so we can get the benefit of various Buffer.* optimizations that may be present in Node.

concat(list: Uint8Array[]): NodeJsBuffer {
    return Buffer.concat(list);
  }

[tadjik1]

Great implementation, decent test coverage, well done @PavelSafronov!