Set the local library at launch via an environment variable

[dasgarner]

Is your feature request related to a problem? Please describe.
When running more than one Player on the same PC (for example if you have a central server which runs many players), it is difficult to automate the deployment of players because the local library folder has to be different for each instance of the Player.

Describe the solution you'd like
An environment variable which can be passed at launch time which overrides the local library setting

[dasgarner]

Please can we also have it possible to override the configuration path location?

[dasgarner]

This would also be useful for launching via VSCode so that the configuration didn't have to sit in the build folder (which is removed sometimes).