$edd_licensed_products inconsistent when used outside is_admin() context

[ashleyfae]

Bug Report

Expected behavior

When I have an individual license key activated (not a pass), I expect EDD to always recognize that.

Actual behavior

If the global $edd_licensed_products is referenced outside of the wp-admin context (is_admin()), then EDD can think I have no license keys entered, when actually I do have one entered.

The problem is that some of our extensions, like Software Licensing, only instantiate the EDD_License class if is_admin(). That means the results of $edd_licensed_products can be inconsistent when checked in a non-admin context.

This is a blocker for #8941. There are two cases where I'm using that variable and getting inconsistent results:

1. When cron is running.
2. In a REST API response.

Information (if a specific version is affected):

PHP Version:

EDD Version (or branch):

WordPress Version:

Any other relevant information:

In the long term we should refactor how add-ons initialize that class, but we cannot rely on updating all add-ons prior to releasing #8941. So I'm making this issue to work on a semi-gross patch, and I'll make a separate issue for a better long-term solution.