debug improvement: single file export to reproduce bugs

[limpkin]

in short: have a way to export a single file to attach to an issue so a debugging person can easily reproduce the bug

[ewowi]

Solved in 5b887e8

Will be merged into main today. https://moonmodules.org/MoonLight/moonlight/overview/ will contain a section 'Reporting issues' explaining the new API button, which shows the rest api. Reopen if after this merge still issues