Don't use embed video on community page

[ChunkyProgrammer]

Before this PR: video attachments for community posts would load an embedded video page (fetching video data, streaming links, etc.) and allowed playing the video within the community page. I imagine this could cause some rate limit issues (especially if there's multiple videos on the community page being loaded)

After this PR: Thumbnail and some video data is shown as a link to the video page. Channel is also shown since I believe it's possible for channels to attach a video from channels that aren't there own.