Make struct spa_node_events for events emited from the main thread
and keep the spa_node_callbacks for the data thread callbacks.
The add_listener method installs the events and it's possible to
install multiple handles. Adding a listener first emits the info
and port_info events when installed, similar to how the PipeWire
proxy bind works.
This removes the need for the spa_pending_queue and makes it easier
to implement the _sync versions.
Add some helpers to make it easier for plugins to emit all the info
to new listeners.
Use the listeners for devices as well.
Add a new struct spa_param_info that lists the available params on
a node/port and if they are readable/writable/updated. We can use
this to replace and improve the PARAM_List and also to notify
property change and updates.
Update elements and code to deal with this new param stuff. Add
port and node info to most elements and signal changes.
Use async enum_params in -inspect and use the param info to know
which ones to enumerate.
Use the port info to know what parameters to update in the
remote-node.
Don't use special callback in node to receive the results. Instead,
use a generic result callback to receive the result. This makes things
a bit more symetric and generic again because then you can choose how
to match the result to the request and you have a generic way to handle
both the sync and async case. We can then also remove the wait method.
This also makes the remote interface and spa interface to objects very
similar.
Make a helper object to receive and dispatch results. Use this in the
helper for enum_params.
Make device use the same result callbacks.
Make the monitor and device emit the info and items when the callbacks
are set. This makes it easier to implement the monitor because there
is much less state to keep around and invalidate etc.
Rework the monitors
Add bluez5 device
