MDEV-26713 Set activeCodePage=UTF8 for windows programs

- Use corresponding entry in the manifest, as described in
https://docs.microsoft.com/en-us/windows/apps/design/globalizing/use-utf8-code-page

- If if ANSI codepage is UTF8 (i.e for Windows 1903 and later)
  Use UTF8 as default client charset
  Set console codepage(s) to UTF8, in case process is using console

- Allow some previously disabled MTR tests, that used Unicode for in "exec",
  for the recent Windows versions

mysql-test/include/check_utf8_cli.inc

@@ -0,0 +1,3 @@
+# Check if utf8 can be used on the command line for  --exec
+# The real check is done in the suite.pm
+#