Implement graceful shutdown for the load balancer server

[vidhvath28]

Changes Made

1. Added signal handling for graceful shutdown.
2. Enhanced the main server loop to support proper resource cleanup.
3. Updated the server log messages to indicate the shutdown process.
4. This improvement ensures that the load balancer maintains a more reliable and user-friendly experience, especially during maintenance or deployment scenarios.

Request for Consideration

Please consider this PR for Hacktoberfest and GSsoC by tagging it with hacktoberfest-accepted and gssoc-ext.

[muruga21]

@vidhvath28 Mergerd !