Moving the part of user_var.test using UCS2 to ctype_ucs.test


mysql-test/r/ctype_ucs.result:
  result update
mysql-test/r/user_var.result:
  result update
mysql-test/t/ctype_ucs.test:
  importing test piece from user_var.test
mysql-test/t/user_var.test:
  using UCS2 in this test fails on non-USC2-capable binaries, so let's move this piece to ctype_ucs.test.
sql/slave.cc:
  changing arg type to uint32* (as what is used in this arg is &thd->db_length which is uint32*)
sql/slave.h:
  changing arg type to uint32*
sql/sql_parse.cc:
  changing arg types to uint32, as what is used in these args is a create_field::length which is uint32.