1. close (https://github.com/apache/doris/issues/16458) for nereids
2. varchar and string type should be treated as same type in bucket shuffle join scenario.
```
create table shuffle_join_t1 ( a varchar(10) not null )
create table shuffle_join_t2 ( a varchar(5) not null, b string not null, c char(3) not null )
```
the bellow 2 sqls can use bucket shuffle join
```
select * from shuffle_join_t1 t1 left join shuffle_join_t2 t2 on t1.a = t2.a;
select * from shuffle_join_t1 t1 left join shuffle_join_t2 t2 on t1.a = t2.b;
```
3. PushdownExpressionsInHashCondition should consider both hash and other conjuncts
4. visitPhysicalProject should handle MarkJoinSlotReference
7bdd854fdc