patch 8.1.0923: terminal dump diff swap does not update file names

Problem:    Terminal dump diff swap does not update file names.
Solution:   Also swap the file name.  Add a test.
diff --git a/src/version.c b/src/version.c
index bf47f97..bb5e0e1 100644
--- a/src/version.c
+++ b/src/version.c
@@ -784,6 +784,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    923,
+/**/
     922,
 /**/
     921,