Relax the checks on xPR configs (still matches spec)
Relax the checks on xPR configs (still matches spec)

Previously, we required that the extra (non-utilized) protected entity fields be *absent* in an xPR config; now we permit them as long as they do not actually contain any entities. For example, an EPR config may now also contain the field 'gwpzRecords' so long as there are no actual GWPZ records configured.

This change is to fulfill a request by ITS which will allow them to leverage their existing MCP config generation code to create valid xPR configs. This PR does not contain any substantive changes.

To quickly double-check that your custom configs remain valid after this change -- which should be the case for all previously-valid configs -- put a `return` statement on line 225 to bypass actual execution of MCP (i.e. the test will exit immediately after checking the config). I have already done this with the WinnForum default configs, the latest ITS draft study guide, and Google's internal tests.
Wireless-Innovation-Forum/Spectrum-Access-System,Wireless-Innovation-Forum/Spectrum-Access-System,Wireless-Innovation-Forum/Spectrum-Access-System,Wireless-Innovation-Forum/Spectrum-Access-System