Simply support 3MF Production Extension.

[cmguo]

Description

This patch adds simple support for [3MF Production Extension]https://github.com/3MFConsortium/spec_production/blob/master/3MF%20Production%20Extension.md).
This patch needs another patch in libSavitar.

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• Test A
  Load old normal 3mf model.
• Test B
  Load 3mf model with 'Production Extension'.
  https://github.com/3MFConsortium/test_suites/tree/master/suite5_core_prod/positive_test_cases.

Checklist:

• My code follows the style guidelines of this project as described in UltiMaker Meta and Cura QML best practices
• I have read the Contribution guide
• I have commented my code, particularly in hard-to-understand areas
• I have uploaded any files required to test this change