Links between endpoints and device nodes are done externally in LUA

This is also what pulseaudio uses, so now the volumes in wpctl match what
pulseaudio tools report and they make a lot more sense from the user's POV

* Fixes set-volume & set-mute
* Re-enables volume & mute status printout for audio nodes

and optimize a little bit so that can stop iterating params
as soon as the info is known

Prints a table recursively with print()

This function loads and enables "api" plugins and makes them
available in the specified callback. This is intended to be used
by interactive scripts in order to get access to "api" plugins
such as the new "default-nodes-api" and "mixer-api"

This module provides an API to get/set volume controls on nodes,
using the same logic as pipewire-pulse, which means it will use
the device Route props when a node is associated with a device
that has this capability

Links items with media role set to existing endpoints. The target of the
endpoints is also configured.

Allows using the endpoint even if a target is not set.

Makes sure core has finished any pending task before finishing the test.

Fixes unespected issues when finding first available target

the previous logic was flawed and would only work for links between
app node <-> device sink node

The main problem observed is when a link that is owned by a WpLink
is removed from the server because one of the linked nodes is gone.
This would cause the APPEARS_ON_REGISTRY flag to go away but the
WpGlobal would still remain in the globals list...

To fix this, forcibly remove the global from the globals list when
it is removed from the registry, even if it is still owned by some
proxy. The proxy at that point is unable to function anyway, because
we make sure to destroy the pw_proxy by removing FEATURE_BOUND when
the global is removed from the registry.

Additionally, ref global->proxy before removing FEATURE_BOUND to
prevent crashing. If the proxy owns the global and the pw-proxy-destroyed
signal causes whoever owns the proxy to drop his reference, _deactivate()
will crash because no-one will be holding a ref to the proxy.

Keeps consistency with PipeWire

The assumption about the global id in wp_registry_prepare_new_global()
was not valid because this function may also be called from the proxy
bound event and this may be before the registry has signalled the
removal of an old global with the same id, for instance

We should instead check this at the point where we expose the global.
If the assertion doesn't hold at that point, we are going to leak an
old WpGlobal, so we must ensure it.