Fix WebSocket proxy URL construction and missing configuration parameter

[Weixi779]

Background

I noticed issue #147 regarding the incorrect WebSocket proxy URL construction. I also saw a similar solution proposed
in PR #149 by @GEverding, which correctly identified the root cause of the problem.

However, PR #149 received a change request from @0xTim asking for tests to verify the proxy URI generation. Since that
PR has not been updated, I have created this PR with the complete fix including the requested test modifications.

Changes

1. Fix proxy URL construction order - Fixes #147

• Changed URL format from ws://host/path:port to ws://host:port/path
• Updated test assertion in testProxy to expect the correct URL format
• Credit to @GEverding for identifying this issue in PR Fix URI and configuration when using proxy #149

2. Add missing configuration parameter

• Pass configuration parameter when connecting through proxy
• Ensures client configuration is properly forwarded to the underlying connection

3. Use correct URI form for wss + proxy connections

• For wss with proxy: use origin-form (/path) after CONNECT tunnel per RFC 7230
• For ws with proxy: continue using absolute-form (ws://host:port/path)
• This fixes potential compatibility issues with strict HTTP/1.1 servers

Tests

• ✅ All existing tests pass (24 tests)
• ✅ testProxy and testProxyTLS verify the fixes work correctly

Note

testBadHost test is skipped in test runs as it hangs indefinitely when attempting to connect to an invalid hostname.
This is a pre-existing issue in the test suite, unrelated to these fixes.