Most subclasses just use the simple function, so just let the base class do it. It makes less code in subclasses. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/906>
Instead of having a helper function that gets called by almost every subclass, just let the base class set the caps fields automatically. Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/906>