CLAP_EXT_AUDIO_PORTS is ignored

[Bremmers]

clap-host always provides audio input and output ports. This isn't as per the specs: a plugin that doesn't implement CLAP_EXT_AUDIO_PORTS has zero audio ports.

This leads to problems if plugin developers use clap-host for testing their plugins.

This code from PluginHost::process() is the problem:

_process.audio_inputs = &_audioIn;
_process.audio_inputs_count = 1;
_process.audio_outputs = &_audioOut;
_process.audio_outputs_count = 1;

[sagantech]

It would be nice if the example host showed how to support multiple outputs and bus configurations as well since this is not so obvious.