MDEV-28471 mysql_install_db.exe does not work with --innodb-page-size=64K

The error message "InnoDB: innodb_page_size=65536 requires innodb_buffer_pool_size >= 20MiB current 10MiB" is the relevant one.

The root cause:
mysql_install_db bootstraps with --innodb-buffer-pool-size=10M.
Small bufferpool is here by design - bootstrap should succeed,
even if there is not much RAM available, bootstrap does not need that much
memory.

For pagesize 64K specifically, Innodb thinks it needs a larger bufferpool,
and thus it lets the bootstrap process die (although the expected behavior
in this case would be to adjust value, give warning and continue)

The workaround:
- pass --innodb-buffer-pool-size=20M, which is suitable for all page sizes.
- check the same limit in MSI custom action.

Also, the patch adds mtr test for 64K page size.

mysql-test/main/mysql_install_db_win.test

@@ -42,6 +42,13 @@ remove_file $log;
 
 rmdir $ddir;
 
+# MDEV-28471 - mysql_install_db.exe fails with --innodb-page-size=64K
+--disable_result_log
+exec $MYSQL_INSTALL_DB_EXE --datadir=$ddir --password=foo -R --innodb-page-size=64K --verbose
+--enable_result_log
+rmdir $ddir;
+
+# Tests with config file
 let $restart_parameters=;
 connection default;