DM advertising prevention filter

A filter on messages should be put in place when the recipient has not yet replied to any of your messages, to prevent interference with conversations. The filter will block messages based on several factors. At least two things will need to have been detected:

- The message contains a link

- The message mentions the word "server" or something similar

 - The message contains a lot of emojis, images, bold/italic text or other eye-catching content

 - Many more things, I'm sure the Discord team are perfectly capable of finding more ways to detect advertising

 Let me know if you like the filter in the replies! I am open to making changes.