Move rest_api to apis/rest. Fixed issue with upload size wasn't saved to...

... Meta data.

CLI should now work with the bepasty-server with new rest APIs.
CLI would not work when the transaction id was capitalized. Flask would automatically lowercase the header key even though it was written as capitalized. Stack trace showed that Flask automatically lowercased the key. Renaming the key to lowercase solved the issue. I don't know if it is something specific with this version.