Integrate UPWARD with Magento

[tjwiebell]

This issue a little open-ended at the moment, but we need to design a solution that allows upward-php to intercept all requests to Magento, and given the request structure, process the request or pass it off to Magento.

Solution 1 - Magento Module

Our initial idea was to have a simple module that would add a Router implementation to RouterList, which would match a specific pattern (ie. /pwa) and then pass that off to upward. After some discussion, it's unlikely there will be a pattern we could match to.

Solution 2 - nginx Config

Discussions led down the thought that the Magento module really didn't provide much value, and routing might be best handled by the web server. If our assumptions are correct, this could work; but we would say any requests not going to /admin or /pub would be routed to upward. This would mean the default frontend would no longer be accessible, but that didn't seem to be a major concern. Could also be an option we explore for Solution 1; if we don't need to support the non-pwa storefront, we could just replace the frontend routers with upward.