Support async for listener

cli.py

@@ -1,10 +1,8 @@
-import asyncio
 import os
-import signal
-from functools import wraps
 
 import click
 
+from mev_inspect.concurrency import coro
 from mev_inspect.db import get_inspect_session, get_trace_session
 from mev_inspect.inspector import MEVInspector
 
@@ -16,25 +14,6 @@ def cli():
     pass
 
 
-def coro(f):
-    @wraps(f)
-    def wrapper(*args, **kwargs):
-        loop = asyncio.get_event_loop()
-
-        def cancel_task_callback():
-            for task in asyncio.all_tasks():
-                task.cancel()
-
-        for sig in (signal.SIGINT, signal.SIGTERM):
-            loop.add_signal_handler(sig, cancel_task_callback)
-        try:
-            loop.run_until_complete(f(*args, **kwargs))
-        finally:
-            loop.run_until_complete(loop.shutdown_asyncgens())
-
-    return wrapper
-
-
 @cli.command()
 @click.argument("block_number", type=int)
 @click.option("--rpc", default=lambda: os.environ.get(RPC_URL_ENV, ""))