Is your feature request related to a problem? Please describe.
With the automatic backup functionality added for config it would should also be quite easy to add a second backup for:

• config
• presets
• custom palettes (can be multiple files)
• custom mappings (can be multiple files)

Describe the solution you'd like
Add buttons to the Security & Update page in the UI to:

• create a copy in the ESP file system for the above files (if files exist). The name should be bku.filename.json, bku for user backup.
• add one button per type, warn user if file(s) already exists and ask to overwrite
• add one button per type to restore user backups, button should be hidden if no corresponding bku file exists