Add static body creation equivalent for all collision shape sibling creations

[ajreckof]

Fix #86626

Just adds an option in the popup menu and handle it the same way it was handled for trimesh collision shapes

[smix8]

The duplicated menu option names need to be fixed.

Imo instead of making the menu even more convoluted than it already is it should be moved to a submenu where users can change the currently hardcoded settings.

[ajreckof]

I reworked it so that it is now in a submenu. On the side while reworking I ended up adding the posibility to add colision shape as sibling on a multi-selection too as it was previously only for static body child.
Here are a few screen shots of how it looked. Feel free to propose improvements:

[smix8]

I tested with a build artifact from this PR and a simple 2x2x2 BoxMesh.

The "Static Body Child" options all work as expected and create StaticBody3D child node with a CollisionShape3D child node that has a ConvexPolygonShape3D resource.

Now what does not seem to work as expected are the "Sibling" options.

I would expect them to do the very same except for leaving out the StaticBody3D node and place the CollisionShape3D node as a sibling with the same ConvexPolygonShape3D resource as with the other options.

The node creation and placement works but not the Shape3D resource creation. Not sure why but the sibling options all created ConcavePolygonShape3D for everything no matter what convex menu option is picked. I would expect them to create the same shape as the other convex options that work.

[smix8]

Seem to work as expected now. I did not encounter any more issues.

[akien-mga]

Thanks!