shiftApiConfig - figure out how to allow client to pass data through to the config

[owensmooth]

At the moment we have to use environment variables for key data like API_HOST, API_TENANT etc.

We need to figure out a way to allow the client to pass what info they want to the config on boot.

We have already tried to use shiftNextConfig in the reference site but that only gets defined when the app has already booted and loaded the homepage. Because we make a call to get the menus when the app is booting we cant use this approach as it is undefined on boot.