This is a follow-up task for WL929. As part of this patch following
changes are done,

  *) Support multiple constraints when check constraint is also
     defined in a column definition.

      WL929 implemented support for check constraint definition
      in a column definition. But multiple constraint definition
      are not accepted when first is check constraint.

      As part of this patch, parser code is changed to support
      the same.

  *) THD::m_cc_adjusted_names_map is removed.

      During ALTER TABLE operation, this member maintained mapping
      from adjusted(temporary) name to actual name of check constraints.
      This was required for the proper error reporting during ALTER
      TABLE operation. But holding this name mapping in THD instance
      looks incorrect.

      As part of this patch, removed THD::m_cc_adjusted_names_map
      member. Added members to Sql_check_constraints_spec,
      dd::Check_constraint classes to hold the temporary names
      and adjusted ALTER TABLE operation code.

  *) Skip invocation of check constraints if column used by check
     constraint is not part of a table write_set.

  *) Fixed few doxygen comment and minor code level issues.

  *) Added test case to verify behavior when before trigger adjusts
     values so that check constraint evaluation passes always.

Change-Id: Ie1202d6b76cb245ac718cede282897759164007b