feat: restrict commands from being used in DMs

- Added `allow_in_dm: false` to various moderation, utility, and role management commands to prevent their usage in direct messages.
- Updated the message event handler to check for the `allow_in_dm` flag and respond appropriately when a DM command is attempted.

src/commands/logs/set_boostembed.rs

@@ -109,6 +109,7 @@ impl crate::commands::command_contract::CommandSpec for SetBoostembedCommand {
                 "+set boostembed color #FF66CC",
             ],
             default_aliases: &["sboostembed"],
+            allow_in_dm: false,
             default_permission: 8,
         }
     }