patch 9.0.1731: blockwise Visual highlight not working with virtual text

Problem: blockwise Visual highlight not working with virtual text
Solution: Reset the correct variable at the end of virtual selection and
          Check for double-width char inside virtual text.

closes: #12606

Signed-off-by: Christian Brabandt <cb@256bit.org>
Co-authored-by: zeertzjq <zeertzjq@outlook.com>
diff --git a/src/version.c b/src/version.c
index 9a1709a..c20dedc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1731,
+/**/
     1730,
 /**/
     1729,