Implement is_adjustable/is_resizable for Slip

The hardened capability traits added `Resampler::is_adjustable`/`is_resizable`
so the capability can be queried through a shared `&dyn Resampler`. `Slip` is
both `Adjustable` and `Resizable`, so it must override both to return `true`;
otherwise the defaulted `false` would under-report its capabilities through a
trait object. Extend the `capability_queries` test to cover `Slip`.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: HEnquist

src/lib.rs

@@ -785,6 +785,13 @@ pub mod tests {
         assert!(boxed.as_adjustable().is_some());
         assert!(boxed.as_resizable().is_some());
 
+        // Slip resamplers are adjustable and resizable, like the async resamplers.
+        let mut slip = Slip::<f64>::new(1024, 2, FixedAsync::Output).unwrap();
+        assert!(slip.is_adjustable());
+        assert!(slip.is_resizable());
+        assert!(slip.as_adjustable().is_some());
+        assert!(slip.as_resizable().is_some());
+
         // Synchronous Fft resamplers are neither.
         #[cfg(feature = "fft_resampler")]
         {

src/slip.rs

@@ -499,9 +499,17 @@ where
         Some(self)
     }
 
+    fn is_adjustable(&self) -> bool {
+        true
+    }
+
     fn as_resizable(&mut self) -> Option<&mut dyn Resizable<T>> {
         Some(self)
     }
+
+    fn is_resizable(&self) -> bool {
+        true
+    }
 }
 
 impl<T> Adjustable<T> for Slip<T>