Add --enable-debug-events flag to CLI

Enables discord.py socket debug events.

Author: amazingakai

redbot/core/_cli.py

@@ -135,6 +135,9 @@ def parse_cli_flags(args):
     )
     parser.add_argument("--version", "-V", action="store_true", help="Show Red's current version")
     parser.add_argument("--debuginfo", action="store_true", help="Show debug information.")
+    parser.add_argument(
+        "--enable-debug-events", action="store_true", help="Enable discord.py socket debug events."
+    )
     parser.add_argument(
         "--list-instances",
         action="store_true",

redbot/core/bot.py

@@ -232,6 +232,9 @@ async def prefix_manager(bot, message) -> List[str]:
         kwargs["max_messages"] = message_cache_size
         self._max_messages = message_cache_size
 
+        if cli_flags.enable_debug_events:
+            kwargs["enable_debug_events"] = True
+
         self._uptime = None
         self._checked_time_accuracy = None