Staging a patch does not copy pak signatures when staging

When creating a patch with pak signing enabled the created output folder contains the pak files from the base release but does not contain the .sig files, even if they were enabled when creating the base release and patch.

The release data created in the Releases/<ReleaseName>/ does also not contain the .sig files.

This is currently worked around by users manually copying the signature files from the original release, or by copying the patch containers out of the output folder of the UAT patch build into a previous release.

Create a base release of with the -createreleaseversion=XYZ argument and pak signing enabled.

Then create a patch with -generatepatch -basedonreleaseversion=XYZ and observe the staged/archived output.