Add an InstallLocation for the installed product

[ader1990]

When using the installer, Cloudbase-Init is installed on Windows and can be queried as a Win32_Product using WMI.

$cbsInit = Get-WmiObject Win32_Product -Filter {vendor="Cloudbase Solutions SRL"}

But the InstallLocation is not present (empty) on the object.
The InstallLocation is required to automatically check the installation status.

According to various sources, this can be achieved by adding a custom action (https://stackoverflow.com/questions/27500705/wix-and-arpinstalllocation)

<CustomAction Id="SetARPInstallLocation"
Property="ARPINSTALLLOCATION" Value="[INSTALLDIR]" />
<SetProperty Id="ARPINSTALLLOCATION" Value="[INSTALLDIR]" After="CostFinalize" />