fix: allow forwarded messages with media in media-only channels by VlaM5 · Pull Request #1419

fix: allow forwarded messages with media in media-only channels by VlaM5 · Pull Request #1419 · Together-Java/TJ-Bot

Forwarded messages that contain media (attachments, embeds, or links)
were incorrectly deleted in media-only channels, because the bot only
checked the message itself, not its MessageSnapshots.

Changes:

Extended messageHasNoMediaAttached() to also check MessageSnapshot contents
Extracted hasMedia() helper method for reuse
Added tests for forwarded messages with and without media