fix(#99): omit url suffix when query params are empty

[tiagosiebler]

Summary

• Some requests have parameters as part of the endpoint, not query parameters. This empty-query-params scenario left a trailing ? in the URL. Fixed the behaviour to only do so if query parameters are in the request. Fixes can't cancel order #99

Additional Information

PR Checklist

As part of the PR, make sure you have:

• No breaking changes / documented all breaking changes clearly.
• Updated & checked that all tests pass.
• Increased the version number in the package.json
• Checked npm install runs without issue.
• Included the package-lock.json, if it changed after npm install
• Checked npm run build runs without issue.
• Updated the endpoint map (optional, if you know how).
• Run llms.txt generator (optional, if you know how).