Change offline mode package cache behaviour

[volllly]

We want to introduce an "offline package" directory where offline packages are downloaded from into the package cache.

Background

Right now when using offline mode the Launcher does not download packages. The Launcher just looks for the packages inside the package cache directory.

When downloading an offline launcher from the portal the packages will be put in a folder packages in the downloaded .zip file.

The original idea was to set the packageCache config parameter to this folder in the downloaded launcher configuration file like this:

fiskaltrust.Launcher.<cashboxid>.zip/
├── packages/
│   ├── <package1>.zip
│   ├── <package2>.zip
│   └── ...
├── launcher.configuration.json
└── fiskaltrust.Launcher.exe

launcher.configuration.json:

{
  // ...,
  "packageCache": "./packages"
}

Poroposed Change to this Process

Instead of changing the configuration to the change package cache folder we want to automatically copy the packages from the "packages" folder next to the launcher executable to the package cache.

fiskaltrust.Launcher.<cashboxid>.zip/
├── packages/
│   ├── <package1>.zip
│   ├── <package2>.zip
│   └── ...
├── launcher.configuration.json
└── fiskaltrust.Launcher.exe

package cache before starting the Launcher:

<package-cache>/

package cache after starting the Launcher:

<package-cache>/
├── <package1>.zip
├── <package2>.zip
└── ...