core: remove parent_id from the global event

Remove the parent_id from the global event. Remove the parent
and owner from the global object.

Use properties instead to mark parents and owners of objects.

Properties are easier to control for client exported objects and
usually a simple parent/child is not enough. For example, a client
exported node has the client as a parent but also the factory that
created the node.

pipewire-jack

@@ -1 +1 @@
-Subproject commit 2d6f9950a5e036f908953727e61e3b3fb02eacf0
+Subproject commit a560e8b92f550268e3e697cfe03bd517664b727d