feature(StoneDB 8.0): Fix codes aboout JoinType

[andyli029]

Is your feature request related to a problem? Please describe.

1. in tianmu:
   enum class JoinType { JO_INNER, JO_LEFT, JO_RIGHT, JO_FULL };

2. in mysql5.7， the jointype is in sql/table.h ,used to assigne value to TABLE_LIST::outer_join, outer_join is uint type.

#define JOIN_TYPE_LEFT    1
#define JOIN_TYPE_RIGHT 2

uint outer_join;

4. in mysql8.0， TABLE_LIST::outer_join data type is bool
   bool outer_join{false};

5. in tianmu
   JoinType JO_LEFT and JO_RIGHT is used to check if it is a left join and check CondType is ON_LEFT_FILTER ；
   JoinType JO_INNER and JO_FULL is used to check if it's CondType is ON_INNER_FILTER；

enum class CondType {
  WHERE_COND,
  HAVING_COND,
  ON_INNER_FILTER,
  ON_LEFT_FILTER,
  ON_RIGHT_FILTER,
  OR_SUBTREE,
  AND_SUBTREE
};

Describe the solution you'd like

So， juse use mysql8.0 TABLE_LIST::outer_join‘s boolean value to decides join type is（JO_LEFT / JO_RIGHT）or (JO_INNER and JO_FULL)

Describe alternatives you've considered

Additional context