Fix arrows3d component alignment under non-uniform scaling

[Cedriq1astaken]

Description

Fixes #5711

When we set normalize = true when using arrows3d, there was an issue where the components (tail, shaft, tip) were misaligned when transformed (this doesn't occur when using LScene since the model matrix is simply the identity matrix). The issue occurred because the code assumed that the directions passed to the positioning step would already be normalized.

(before)

The fix is to remove this assumption and always normalize the directions before positioning the components.

(after fix)

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist

• Added an entry in CHANGELOG.md (for new features and breaking changes)
• Added or changed relevant sections in the documentation
• Added unit tests for new algorithms, conversion methods, etc.
• Added reference image tests for new plotting functions, recipes, visual options, etc.