Implement Klipper Upload

[GerritPlehn]

Hey! I implemented a basic upload for Klipper printers as mentioned in #2.

• Refactored printer "types" into their own sub-classes
• Classes need to provide their own implementations for connecting, disconnecting and uploading
• added configuration key type, possible values being Bambu and Klipper

Since I don't own a Bambu printer, someone would need to test if I didn't break the Bambu upload while refactoring.

I threw the Printer subclasses into the same file for now. Depending on how many printers should be implemented in the future, we should probably move them to their own files.

Open for any feedback of course. Happy Printing!

[GerritPlehn]

Didn't see #4 when I hacked this together. Since we had a very similar approach, I'd suggest merging it before this one. Then I can refactor this PR to fit the other PR.

[d3vyce]

I've just added a test in the connect function on my branch #4, a bit like you did. If you think something is missing, don't hesitate, just to have a clean model before adding more printer types.