Modmails with too large an attachment are not handled

[R3TRO04]

Description

If the server Sam is running on does not have enough server boosts, an exception is thrown that is not handled. Sam never informs the user what happened to the modmail.

What we need to change

The exception should be caught and then the sender should be informed that the modmail was not sent because the attachment was too big.

[PKlempe]

So if I understand this correctly, the problem is that if a user has Discord Nitro and the server on which the bot is running doesn't have enough Server Boosts, the bots upload limit is 8MB while the user probably has 50 or 100MB (depending on which kind of Nitro he bought). This should mean that a user is able to invoke the modmail command with a larger file attachment, but SAM can't post the message in the configured modmail channel because he isn't allowed to upload the file. Interesting... 🤔

I think SAM should at least inform the user about this problem and suggest using a link from a file sharing plattform instead.