utils: implement g_cancellable_new_with_timeout

lib/utils/mu-utils-file.hh

@@ -24,6 +24,7 @@
 #include <cinttypes>
 #include <sys/stat.h>
 
+#include <gio/gio.h>
 #include <utils/mu-option.hh>
 #include <utils/mu-regex.hh>
 
@@ -157,6 +158,17 @@ std::string join_paths(S&& s, Args...args) {
 }
 
 
+/**
+ * Like g_cancellable_new(), but automatically cancels itself
+ * after timeout
+ *
+ * @param timeout timeout in millisecs
+ *
+ * @return A GCancellable* instances; free with g_object_unref() when
+ * no longer needed.
+ */
+GCancellable* g_cancellable_new_with_timeout(guint timeout);
+
 } // namespace Mu
 
 #endif /* MU_UTILS_FILE_HH__ */