lib/query,parser: update to use mu-message-fields

lib/mu-query.hh

@@ -21,11 +21,13 @@
 #define __MU_QUERY_HH__
 
 #include <memory>
+#include <optional>
 
 #include <glib.h>
 #include <mu-store.hh>
 #include <mu-query-results.hh>
 #include <utils/mu-utils.hh>
+#include <mu-message.hh>
 
 namespace Mu {
 
@@ -41,10 +43,11 @@ public:
 	 *
 	 * @return the query-results, or Nothing in case of error.
 	 */
-	Option<QueryResults> run(const std::string& expr        = "",
-	                         MuMsgFieldId       sortfieldid = MU_MSG_FIELD_ID_NONE,
-	                         QueryFlags         flags       = QueryFlags::None,
-	                         size_t             maxnum      = 0) const;
+
+	Option<QueryResults> run(const std::string&			expr	     = "",
+				 std::optional<Message::Field::Id>	sortfield_id = {},
+				 QueryFlags				flags	     = QueryFlags::None,
+				 size_t					maxnum	     = 0) const;
 
 	/**
 	 * run a Xapian query to count the number of matches; for the syntax, please