block: Implement SparseCapable trait for RawFileDiskAio

Add disk_file::SparseCapable trait implementation for
RawFileDiskAio. Delegates to probe_sparse_support() to
detect whether the underlying file supports hole-punching.

Signed-off-by: Muminul Islam <muislam@microsoft.com>

block/src/raw_async_aio.rs

@@ -101,6 +101,12 @@ impl disk_file::Geometry for RawFileDiskAio {
     }
 }
 
+impl disk_file::SparseCapable for RawFileDiskAio {
+    fn supports_sparse_operations(&self) -> bool {
+        probe_sparse_support(&self.file)
+    }
+}
+
 pub struct RawFileAsyncAio {
     fd: RawFd,
     ctx: aio::IoContext,