[PP-537] Introduce nominal_layer_height

[Frederic98]

PP-537: Introduce nominal_layer_height

Description

This PR introduces the nominal_layer_height setting. This is the layer height that the final part should have. The real layer_height and layer_height_0 become children of this setting.

Rationale

For the Factor 4, we multiply the layer height with the material shrinkage factor. This is done so that an object of 20mm high printed with a 0.2mm layer height, will still have exactly 100 layers. This improves the dimensional accuracy, because otherwise the object might not have an exact whole number of layers.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Printer definition file(s)
• Translations

How Has This Been Tested?

Ran Cura from source with these changes

Test Configuration:

• Operating System: Ubuntu

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

[github-actions]

Test Results

23 370 tests  ±0   23 286 ✅  - 82   46s ⏱️ -8s
     1 suites ±0        2 💤 ± 0 
     1 files   ±0       82 ❌ +82 

For more details on these failures, see this check.

Results for commit 2999b9d. ± Comparison against base commit 382b98e.