Various improvements

[frankrousseau]

Problem

• Episodes can't have file paths
• Bots can't be modified if the default user is protected
• Malformed trees leads to server error when creating an output file
• 2FA can't be enforced on the frontend side
• Source files is not always needed when uploading previews
• Preview files lack of flexible field for extra metadata
• Plugins are not so intuitive to set up

Solution

• Add episode support to file path generation
• Add a condition for protected user: they should not be bots
• Handle MalformedTreeException exceptions
• Add an environment variable to force 2FA
• Add an environment variable to not save source files during a file upload
• Add a JSONB data field to preview files
• Improve logging and naming of plugins commands and templates