[GuideLLM Refactor] Entrypoint: Reintroduce changes from main (#363)

## Summary

Reintroduces a few changes from main

---------

Signed-off-by: Samuel Monson <smonson@redhat.com>

Author: sjmonson

src/guidellm/__main__.py

@@ -104,6 +104,7 @@ def decode_escaped_str(_ctx, _param, value):
 
 
 @click.group()
+@click.version_option(package_name="guidellm", message="guidellm version: %(version)s")
 def cli():
     """
     Main entry point for the GuideLLM command-line interface.

src/guidellm/logger.py

@@ -71,7 +71,8 @@ def configure_logger(config: LoggingSettings = settings.logging):
     logger.add(
         sys.stdout,
         level=config.console_log_level.upper(),
-        format="{time} | {function} | {level} - {message}",
+        format="<green>{time:YY-MM-DD HH:mm:ss}</green>|<level>{level: <8}</level> \
+        |<cyan>{name}:{function}</cyan>:<cyan>{line}</cyan> - <level>{message}</level>"
     )
 
     if config.log_file or config.log_file_level: