[Bug]: UI not using presign for uploading objects

[Isan-Rivkin]

What happened?

As part of the work on IAM Minimal Permissions, we require lakeFS to work with presign URL only. For Get / Download it works as expected but for upload the UI ignores the presign setting and calls lakeFS API with presign=false.

Incase of installation with minimal IAM permissions, trying to upload via the UI will fail.