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/main/grant_utf8_cli.result

@@ -0,0 +1,8 @@
+set names utf8;
+create user юзер_юзер@localhost;
+grant select on test.* to юзер_юзер@localhost;
+user()
+юзер_юзер@localhost
+revoke all on test.* from юзер_юзер@localhost;
+drop user юзер_юзер@localhost;
+set names default;