transform message to into an answer to message above
people are often sloppy in using answers to messages and just type it to the channel when it should be an answer to the message above.
I propose a button visible to the author and admins that allows to transform a message into an answer to the message above.
I hope it'll help to create more consistency in the usage of the answer/thread feature.
Planned with this ticket: https://mattermost.atlassian.net/browse/MM-35848