Add modify batch orders feature #647

[khanbekov]

Implementation of order batches modification and test for it. Presented in the official api of binance: https://developers.binance.com/docs/derivatives/usds-margined-futures/trade/rest-api/Modify-Multiple-Orders

[khanbekov]

Hello, I wanted to add a little more detail about this commit.

This PR adds support for the Modify Multiple Orders endpoint in Binance’s USD-Margined Futures API. I noticed this feature wasn’t implemented in the library while working on my trading system. This is very handy when you need to update multiple orders at once, rather than canceling and re-creating them or modifying them one at a time. This reduces the load on the API, which allows you to avoid a ban from the exchange API.

The implementation follows the style of existing batch order methods (like placing and canceling), so it should feel consistent. I’ve also added tests to ensure everything works as expected.

Let me know if you have any feedback! Thanks. @adshao

[khanbekov]

Hello.
Review again, please. I've made requested changes. Thanks @adshao