Distributed foreign table creation fails with confusing message when column types are different

```sql
create table t1(a int unique, b int);
create table t2(a bigint references t1(a), b int);
select create_distributed_table('t1', 'a');
select create_distributed_table('t2', 'a');
```

Result
```
ERROR: cannot create foreign key constraint
DETAIL: Foreign key constraint can only be created on co-located tables.
```
Expected:
Error message should direct user to use same types in referring and referred columns.