Update 0.3.0 - preview 6

Hey folks! This is the last planned update for the 0.3.0-preview branch.

• UI scaling - if the UI is straining your eyes, you can now scale it! Go to Main Menu -> Settings to do so (you can scale from 50% to 400%)
• Engraving depth per face - engraving depth can be overriden an set separately for the selected face
• There are "engraving width" and "engraving height" info boxes now, below face settings
• Fixed an issue with some almost-straight Beziers being interpreted as segments too aggresively
• Some other minor fixes

I'm planning on releasing the updates of the preview branch to main branch next week.

Happy making!