Large `!remaining` data does not send message

An excessively large !remaining output will not get properly split into message chunks, preventing the message from being DM'd to the player, showing a RangeError (SPLIT_MAX_LEN) error in the logs. The message chunking utility only uses line breaks for splitting large messages, but the !remaining output does not use line breaks. Add a comma as a potential chunk split character.

Also, while it does correctly catch the exception (and prevent a crash), the error is not sent to any configured telemetry outputs.