Fix StreamingFlacSink compilation errors

- Fix import paths to use public pmoaudio API instead of private modules
- Change AudioError::ConfigurationError to ProcessingError
- Use Node::new_with_input() instead of non-existent Node::new()
- Fix borrow checker issues in IcyClientStream::poll_read()
- Use flatten() on metadata getters to unwrap Result<Option<T>>
- Fix chunk.get_sample_rate() to chunk.sample_rate()
- Remove get_album_artist() call (not in TrackMetadata trait)
- Update pmoparadise Cargo.toml to enable pmoserver feature for axum
- Simplify example init_logging() call to match new pmoserver API

pmoparadise/Cargo.toml

@@ -91,7 +91,7 @@ cache = []
 # Active le support pmoaudio node (RadioParadiseStreamSource)
 pmoaudio = ["dep:pmoaudio", "dep:pmoflac", "dep:pmometadata", "dep:futures-util"]
 # Active le support complet avec playlist (pour les exemples avancés)
-full = ["pmoaudio", "dep:pmoaudio-ext", "pmoconfig", "dep:pmoserver"]
+full = ["pmoaudio", "dep:pmoaudio-ext", "pmoconfig", "pmoserver"]
 
 [dev-dependencies]
 # Tests