Mod: Show regressions in shape colouring

[wwmayer]

This PR demonstrates the known regressions of the recently merged material branch:

• Changing the transparency after setting color per face will reset them
• The result of boolean operations or compound doesn't inherit the colour of its input objects
• If colour is set per face to a boolean operaton object then saving and restoring the file causes weird rendering behaviour because material binding is set to PER_PART but only a single colour is defined
• If a shape inside a part container has set colour per face then saving and restoring as STEP file causes weird rendering behaviour for the same reason
• Shape binder or datum objects don't show the correct default shape colour

[wwmayer]

As expected these tests fail:

FAILED: testMultiFuse (parttests.ColorPerFaceTest.ColorPerFaceTest.testMultiFuse)
FAILED: testMultiFuseSaveRestore (parttests.ColorPerFaceTest.ColorPerFaceTest.testMultiFuseSaveRestore)
FAILED: testTransparency (parttests.ColorPerFaceTest.ColorPerFaceTest.testTransparency)
FAILED: testDefaultColor (TestPartDesignGui.TestDatumPlane.testDefaultColor)
FAILED: testDefaultColor (TestPartDesignGui.TestShapeBinder.testDefaultColor)
FAILED: testDefaultColor (TestPartDesignGui.TestSubShapeBinder.testDefaultColor)
FAILED: testSaveLoadStepFile (TestImportGui.ExportImportTest)

The MacOS build doesn't fail because it doesn't run the GUI tests.

[FlachyJoe]

I thought that tests are created to avoid regression, what is the point of merging known failing tests?

[wwmayer]

Are you aware of the recent regressions due to the merged material branch? These tests do only fail because the broken code IS already in main. So, it's exactly the other way around: the broken has already been merged and these tests just show in a testable way that the code is broken.

To confirm that they test the correct things I have used them with an older version before the material branch was merged and there they all pass

With #13332 a new PR is available that makes many tests pass now. That PR I have rebased and force-pushed to confirm that most the tests will pass. This way it's easier to see that it (almost) works.

[FlachyJoe]

I understand but I think I'd keep the tests in my dev branch until the corrective was ready. With this merge all the new submitted PR fail so it's harder to know their quality.