STL File support

✨ feat(input.py): add support for binary and ascii STL files to ScannedObject class The ScannedObject class now has a static variable called authorised_extensions which contains a list of file extensions that are supported by the class. This improves the readability of the code and makes it easier to maintain. The ScannedObject class now also supports binary and ascii STL files, which increases the flexibility of the class and allows it to handle more file formats.