- Add directConnection=true when using SSH tunnel to prevent replica set discovery
- Parse MongoDB connection string to extract server/port for SSH tunnel creation
- Replace multi-host URLs with single tunnel endpoint (127.0.0.1:port)
- Add logging for SSH tunnel connection debugging (DBGM-00199, DBGM-00200, DBGM-00201)

This fixes the issue where MongoDB replica set connections would fail when using
SSH tunnels, as the driver would try to discover and connect to other replica set
members which are not accessible through the tunnel. The directConnection parameter
forces the driver to only use the specified host, which is the standard approach
used by other database tools like Studio 3T.

Fixes connection timeouts and 'Invalid URL' errors when connecting to MongoDB
replica sets through SSH tunnels with Database URL mode.