block_util: Port synchronous RAW file to AsyncIo trait

Based on the synchronous RAW file implementation present in the qcow
crate, we created a new raw_sync module in block_util that ports this
synchronous implementation to the AsyncIo trait.

The point is to reuse virtio-blk asynchronous implementation for both
synchronous and asynchronous backends.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

block_util/Cargo.toml

@@ -12,6 +12,7 @@ io_uring = []
 io-uring = ">=0.4.0"
 libc = "0.2.82"
 log = "0.4.13"
+qcow = { path = "../qcow" }
 serde = ">=1.0.27"
 serde_derive = ">=1.0.27"
 serde_json = ">=1.0.9"