This pull request introduces a new check for Discord message attachments to ensure they do not exceed the 8 MB file size limit, and adds localized error messages in both English and French to inform users when their attachments are too large.

Attachment size validation:

• Added a check in guild_messages_handler.rs and threads.rs to prevent forwarding or creating channels for messages with attachments larger than 8 MB. If such an attachment is detected, the user receives a system message and the operation is aborted. [1] [2]

Internationalization updates:

• Added a new English error message (discord.attachment_too_large) to inform users about the attachment size limit.
• Added a French translation for the new error message to ensure users receive the correct notification in their preferred language.