fix: add toAddrType in WithdrawRequest

[petarzarkov]

Summary

Extend WithdrawRequest

PR Checklist

As part of the PR, make sure you have:

• [x ] No breaking changes / documented all breaking changes clearly.
• [x ] Updated & checked that all tests pass.
• [ x] Increased the version number in the package.json
• [ x] Checked npm install runs without issue.
• [ x] Included the package-lock.json, if it changed after npm install
• [x ] Checked npm run build runs without issue.
• Updated the endpoint map (optional, if you know how).
• Run llms.txt generator (optional, if you know how).

[petarzarkov]

@tiagosiebler Yo, take a look when you can, it's a small type addiotion

[tiagosiebler]

Thanks for the PR!

[tiagosiebler]

Released: https://github.com/tiagosiebler/okx-api/releases/tag/v3.0.8