[#1312] Refactor ResultSetAdaptor#getBlob

Since Vert.x 4.3.1, Oracle might return a class that's only
available in the vertx-sql-oracle client when using Row#getValue
for a blob column.

This means that we cannot check for the type of the instance and
we have to make a last attempt hoping that the value can be returned
as Buffer. It will throw a ClassCastException if that's not the case.

Author: DavideD

hibernate-reactive-core/src/main/java/org/hibernate/reactive/adaptor/impl/ResultSetAdaptor.java

@@ -720,17 +720,14 @@ public Blob getBlob(String columnLabel) {
 			return null;
 		}
 
-		if ( value instanceof Buffer ) {
-			return BlobProxy.generateProxy( ( (Buffer) value ).getBytes() );
-		}
-		else if ( value instanceof String ) {
+		if ( value instanceof String ) {
 			return BlobProxy.generateProxy( ( (String) value ).getBytes() );
 		}
-		else if ( value instanceof byte[] ) {
+		if ( value instanceof byte[] ) {
 			return BlobProxy.generateProxy( (byte[]) value );
 		}
 
-		throw new IllegalArgumentException( "Unexpected type: " + value.getClass() );
+		return BlobProxy.generateProxy( row.getBuffer( columnLabel ).getBytes() );
 	}
 
 	@Override