fix: ensure to use pathname instead of '/' when clearing query parameters

[frederikprijck]

Changes

Using window.history.replaceState({}, '', '/'); can, and will cause issues when the application is not served from root.

That particular code has the only purpose to remove the query string, not change the URL. Changing the URL happens only when we are using the router.

Whenever a user would handle the code exchange on https://example.com/foo?code=abc, we would update the URL to be https://example.com, instead of https://example.com/foo.

References

Closes #424

Testing

• This change adds unit test coverage
• This change adds integration test coverage
• This change has been tested on the latest version of the platform/language

Checklist

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