Feature request: reformat / delete all models in internal storage

[cibomahto]

When uploading a model over WiFi from PrusaSlicer, I got the message that internal storage was full. First, it wasn't clear how to delete print job files. The only way I could find to do so was to swipe on them one-by-one from the print menu (which seems completely unrelated to the task). Since I hadn't done this before, the printer had around 80 print jobs to delete, which was very tedious! It would be excellent if there was a function to just remove them all in go,

[ankineri]

This is my crude JS to do this: https://gist.github.com/ankineri/37706968a097c0b24d6590b1fe4bdcf8
Just open the printer page in a browser and run the above in console.

After it gets the list of files, run await deleteFiles(allFiles) to delete all files or await deleteFiles(allFiles, true) to delete them recursively.