Redact sensitive query params in HTTP error messages

[trasnake87]

Summary

• Added redact_url_query() static helper function that replaces query parameter values with [redacted] while preserving parameter names, separators, and URL structure
• Updated error messages in both synchronous and asynchronous http_request::perform() methods to redact URLs before including them in error output

This prevents sensitive tokens or credentials in query parameters from leaking into error messages/exceptions.

Example

Before:

Failed to perform http request to https://api.example.com/auth?token=secret123&key=abc456 : CURLcode 6

After:

Failed to perform http request to https://api.example.com/auth?token=[redacted]&key=[redacted] : CURLcode 6

Notes

• Only lib/playapi/util/http.cpp is modified (no unrelated file changes)
• No new headers or external dependencies required
• The helper is deliberately simple: it redacts all query parameter values uniformly, preserving keys and separators for debugging utility
• Debug-only printf statements (guarded by #ifndef NDEBUG) are left unchanged per the issue scope, as they are already disabled by default in release builds

Addresses the same problem described in #3.