Move packages to anywhere

[laicasaane]

As for Unity 2018 there is a Packages folder which is used by the Unity Package Manager and this folder is located at the project root. Currently there is no way to copy this folder into ProjectRoot as it does for ProjectSettings. There should be a way to move packages anywhere, not just special places like Assets, Plugins.

P/S: This might be similar to #73 but my request is for configuration files (ProjenyProject.yaml).