feat: add cli argument to display runner version (#21)

Closes #19

### Summary of Changes

- display version fetched from metadata for --version and -V args (using
importlib.metadata.version)

---------

Co-authored-by: megalinter-bot <129584137+megalinter-bot@users.noreply.github.com>

src/safeds_runner/server/main.py

@@ -3,6 +3,7 @@
 import argparse
 import json
 import logging
+from importlib.metadata import version
 
 import flask.app
 import flask_sock
@@ -178,6 +179,12 @@ def main() -> None:  # pragma: no cover
 
     parser = argparse.ArgumentParser(description="Start Safe-DS Runner on a specific port.")
     parser.add_argument("--port", type=int, default=5000, help="Port on which to run the python server.")
+    parser.add_argument(
+        "-V",
+        "--version",
+        action="version",
+        version="%(prog)s {version}".format(version=version("safe-ds-runner")),
+    )
     args = parser.parse_args()
     logging.info("Starting Safe-DS Runner on port %s", str(args.port))
     # Only bind to host=127.0.0.1. Connections from other devices should not be accepted