[Feature Suggestion] Add new abiity for Quick Posts Tools

This extensions gives us power to do multiple changes for topics. But for posts will be great to have some features. One that I miss most is the ability to change the author of all posts of a topic, having a way to select multiple posts and then apply the author change would be awesome. Block messages or delete message could be a thing too. (But those options are available on the moderation page so, not extremely necessary)