Export to 3MF with Custom Parameters

[LittleSound]

Allow customizing 3MF settings during export, like printer model and material type, and whether to activate the 3D printing wipe tower. Also, remember user choices.

[phreakocious]

PR for this will be incoming when #13 is merged.

[LittleSound]

Okay. I will review this.

[LittleSound]

I've merged it, thank you.