feat(gcs): add support for gcs append

[cuichenli]

Fixes #1452

[Xuanwo]

Hello @cuichenli, thank you for submitting this PR!

I will temporarily close the PR to give you more space to improve it. By closing on-going (instead of on-reviewing) PR allow both of us foucing our own work. Please note that closing the PR does not mean rejection; feel free to reopen it when you are ready for further review or feedback.

Thank you again and have a great day!

[Xuanwo]

I apologize for closing this pull request. Our policy has been updated, and we will no longer close pull requests so hastily. Additionally, I have recently learned that once a maintainer closes a pull request, it cannot be reopened.

[cuichenli]

I apologize for closing this pull request. Our policy has been updated, and we will no longer close pull requests so hastily. Additionally, I have recently learned that once a maintainer closes a pull request, it cannot be reopened.

No problem at all! I apologize for the delay in updating the PR as I have been busy with other tasks.

I have made some changes to use the streaming API in the latest commit. However, I must admit that the implementation is not optimal. The main issue arises during the final chunk, where we need to specify the final chunk size. Since this size is unknown until the user invokes the close function, the implementation became a bit tricky. I attempted to send a POST request with an empty body, but unfortunately, it did not work. As an alternative, I recorded the last copy sent and when the user invokes the close function, I resend it with the correct headers. I am uncertain whether this approach is acceptable, but I cannot think of a better solution at this time.

Please take a look. Thanks

[cuichenli]

I have updated based on the comments, please review.

[Xuanwo]

Great! Thanks a lot!