use multipart copy for s3

[icewind1991]

Switches to the multi part copies to support copying files >5GB (rename uses copy under the hood for ext s3)

Fixes #24540

Unfortunately my testing is limited by minio seemingly not having the 5GB limit on normal copy.

[icewind1991]

/backport to stable27

[backportbot-nextcloud]

The backport to stable27 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable27
git pull origin stable27

# Create the new backport branch
git checkout -b fix/foo-stable27

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable27

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport