Conditionally append parameters to GET requests

[n7studios]

Summary

Conditionally appends parameters to GET requests, as some requests with no parameters resulted in ? being appended and a redirect being performed as part of the API request:

Testing

Existing tests pass.

Checklist

• I have written a test and included it in this PR
• I have run all tests and they pass
• The code passes when running the PHP CodeSniffer
• Code meets WordPress Coding Standards for PHP, HTML, CSS and JS
• Security and Sanitization requirements have been followed
• I have assigned a reviewer or two to review this PR (if you're not sure who to assign, we can do this step for you)

[noelherrick]

Thoughts on standardizing on a library for URI manipulation (some light googling brought up https://uri.thephpleague.com/)? I don't know how often it comes up but it might avoid issues such as this.

[n7studios]

Thoughts on standardizing on a library for URI manipulation (some light googling brought up https://uri.thephpleague.com/)? I don't know how often it comes up but it might avoid issues such as this.

I don't think it's needed. We're using WordPress standard wp_remote_* functions, which handle most URI manipulation here. I'll likely submit a patch to the WordPress core trac to have this handled upstream in their HTTP request functions.