[Security] WebSocket ssl Parameter Accepts False/None Without Warning

## Bug Name
WebSocket ssl Parameter Accepts False/None Without Warning

## Attack Scenario
The WebSocket init_connection method passes configuration.https_agent directly to aiohttp.ws_connect(ssl=...). When ssl=False, aiohttp disables SSL verification entirely without any warning from the SDK.

## Impact
A user who sets https_agent=False would silently disable TLS certificate verification for all WebSocket connections, enabling MITM attacks.

## Components
File: common/src/binance_common/websocket.py (lines 164-170, 182-188). ssl parameter passed from configuration.https_agent.

## Reproduction
1. Create WebSocket configuration with https_agent=False.
2. Connect to WebSocket API.
3. SSL verification is silently disabled -- no warning or error.

## Fix
Add a validation check: if https_agent is False, raise a warning or error. Document the security implications clearly.

## Details
Finding ID: SEC-05
Severity: Low

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Researcher: Independent Security Researcher -- Mefai Security Team