fix(testclient): exclude query sting from raw_path before passing to app

[raptium]

Summary

As we discussed in #2692, this commit updates the testclient so that query string is excluded from raw_path
for both HTTP and WebSocket.

Checklist

• I understand that this PR may be closed in case there was no previous discussion. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.