Arch: Fix ArchFrame

[Roy-043]

A previous PR broke ArchFrame for non planar Base objects (single lines).

This PR fixes this and also simplifies the alignment algo by relying on the built-in capabilities of FreeCAD.Rotation(). The resulting alignments are more logical in general.

Additionally:

• The first Base Point now matches the Placement.Base of the profile. This makes more sense than using the CenterOfMass of its face.
• Offset is performed before Rotation. Again because this makes more sense.
• Replaced obj.Profile.isDerivedFrom("Part::Part2DObject") check with obj.Profile.Shape.findPlane() check. The latter is more reliable and flexible. A Part::Part2DObject does not have to be planar. And f.e. a Std_Part that contains a profile can now be used.

Forum topics:
https://forum.freecadweb.org/viewtopic.php?f=23&t=65266
https://forum.freecadweb.org/viewtopic.php?f=23&t=65342

• Your pull request is confined strictly to a single module. That is, all the files changed by your pull request are either in App, Base, Gui or one of the Mod subfolders. If you need to make changes in several locations, make several pull requests and wait for the first one to be merged before submitting the next ones
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And please remember to update the Wiki with the features added or changed once this PR is merged.
Note: If you don't have wiki access, then please mention your contribution on the 0.20 Changelog Forum Thread.

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[freecadci]

for feature branch PR_5479. Pipeline 462151172 was triggered at 10c49de. All CI branches and pipelines.

[yorikvanhavre]

Thanks for the follow-up!
I didn't test yet but will do!