Improve .csproj package installation process
The current .csproj package install runs separate tap processes in succession and hopes everything goes well, but this is not always very stable, and it is quite inefficient. Since OpenTAP Images have been implemented, we can now resolve an image and install it in one go instead. This should be much faster and more robust.
This should also allow us to give better error messages in case an installation cannot be resolved, which is discussed in #801