Feat/issue 605 debug logging via env variable (#608)

* feat: Debug Logging via Environment Variable

* refactor: deleted libp2p/utils.py

* fix: double messages logging fix

* doc: add logging info to getting_started.rst

libp2p/utils/version.py

@@ -0,0 +1,22 @@
+from importlib.metadata import (
+    version,
+)
+import logging
+
+logger = logging.getLogger("libp2p.utils.version")
+
+
+def get_agent_version() -> str:
+    """
+    Return the version of libp2p.
+
+    If the version cannot be determined due to an exception, return "py-libp2p/unknown".
+
+    :return: The version of libp2p.
+    :rtype: str
+    """
+    try:
+        return f"py-libp2p/{version('libp2p')}"
+    except Exception as e:
+        logger.warning("Could not fetch libp2p version: %s", e)
+        return "py-libp2p/unknown"