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.
Make it possible to assign an arbitary node as the port mixer.
Also remove dynamically added ports.
Improve negotiation and allocation on the mixer ports
Add some more SSE optimisations
Move float mixer from the audio dsp to the port
Remove pw_node_get_free_port() and do things more explicitly.
Handle mixer ports in client-node
