And we restore the previously removed helper and incorrectly replaced by
the `is-direct-child-of-root?`.
In penpot exists two concepts: root and root-frame; root is the
artificially created shape that represents the ROOT, and root-frame
means a frame that is shape of frame type which is a direct children
of ROOT.
Also optimizes some functions for faster shape and rect props
access (there is still a lot of work ahead optimizing the rest of
the functions)
Also normalizes shape creation and validation for ensuring
correct setup of all the mandatory properties.
