Add an integrated report feature

This appears to exist on Mobile when long tapping a message, but there desperately needs to be an expedited process on PC available to more than just DMs and Server Mods (via Report Raid and post deletion menu). What ends up happening now since PC lacks a report feature is that when you report something to Trust & Safety and the offending user deletes it a day later and before a response is made, your report gets declined because the post is gone. This was posted before around 2 years ago in "Other" but I did not want to bump a post that old. https://support.discord.com/hc/en-us/community/posts/1500000997882-Add-A-Report-User-Feature