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.
Only allow properties inside objects, this makes it easier to
iterate the object, which is needed for efficiently processing
control streams.
Add a choice type to mark variable properties.
SPA_TYPE_Enum -> SPA_TYPE_Id to avoid confusion with choice enum
Make it easier to allocate and initialize properties on the stack
Make more efficient methods to make objects.
spa_io_control_range -> spa_io_range
Add helpers for sequence and control pod objects
Implement control properties in audiotestsrc, update test example.
SPA_ID_* -> SPA_TYPE_*. We use 'type' for all registered types.
ID refers to either a registered type or an enum.
Improve introspection of object ids. Make 0 an invalid enum and
use it to look up the object id type.
Move some type-info files together.
Swap type and id of the object, we first specify the type and then
the id because the meaning of the id depends on the object type.
Param ids and IO ids are now simple enums.
Move some type info in one place, delete some type-info files
Fix type debug
Make audio layout an enum
Mark more enums as enums in types so they show us with their names in
the debug.
Do not use dynamic types anymore. The reason is that it's difficult:
- to maintain a shared type database over a network.
- the extra overhead when translating between processes and for
maintaining the translation tables.
- race conditions in translating in RT-threads, this is a problem
because we want to make event streams.
We now have simple enums with types and extension points for all
types. This is also nicer to use in general.
We don't need the mapper anymore or pass strings around as types.
There is a parallel type info system to get more info about ids and
enums and their hierarchy. It can also be used for debugging.
