Presigned Storage URLs not used for image generation

[kuzpactor]

Overview of the Issue

Right now in order to upload an image (like previously brewn qcow2 file) you have to either enable public access on your bucket, or come up with a more-or-less complicated set of ACLs around it.

Without that, image cannot be created because Compute ImageService.Create has no permissions to the object.
One way out of this situation is to use URL Presigning, which BTW is already used in case of importing other artifacts already present in Object Storage.

To be honest, I'm not really sure if this is a bug, but right now it definitely makes working with YC significantly more involved that it potentially could be.

Reproduction Steps

1. Create an empty bucket with default permissions.
2. Point packer to that bucket, with whatever file that ends with .qcow2
3. Receive an error after Compute launches their op: rpc error: code = InvalidArgument desc = url source not found

Plugin and Packer version

From 1.1.2

Simplified Packer Buildfile

source "file" "base" {
    source = "testing.qcow2"
    target =  "testing.qcow2"
}

build {
    sources = ["sources.file.base"]

    post-processors {
        post-processor "yandex-import" {
            service_account_key_file = "key.json"
            folder_id = "b48..."
            service_account_id = "f08..."
            bucket = "kuzpactor-service"
        }
    }
}

Operating system and Environment details

MacOS, 13.4.1 (22F82), on Apple Silicon (M1).
The plugin is launched with patch from #83, because otherwise the file ends up in the wrong installation.

Log Fragments and crash.log files

==> file.base (yandex-import): Uploading file testing.qcow2 to bucket kuzpactor-service/packer-import-1692557311.qcow2...
==> file.base (yandex-import): Source of Image creation: object source, url: https://storage.il.nebius.cloud/kuzpactor-service/packer-import-1692557311.qcow2
==> file.base (yandex-import): Creating Yandex Compute Image test-image-1692557311 within operation "alk9aaj99asv7v41qak6"
==> file.base (yandex-import): Waiting for Yandex Compute Image creation operation to complete...
2023/08/20 20:48:47 packer-plugin-yandex plugin: 2023/08/20 20:48:47 error: failed to create Yandex Compute Image: operation (id=alk9aaj99asv7v41qak6) failed: rpc error: code = InvalidArgument desc = url source not found
2023/08/20 20:48:47 [INFO] (telemetry) ending yandex-import