**Describe the bug**
Here's my table:
```sql
CREATE TABLE table2
(
        EventDate Date,
        Id Int32,
        Value Int32
)
Engine = MergeTree()
PARTITION BY toYYYYMM(EventDate)
ORDER BY Id;
```

Modify default value (intentionally wrong):
```
>>> alter table table2 modify column Value default 'some_string';

ALTER TABLE table2
    MODIFY COLUMN `Value` DEFAULT 'some_string'

Ok.

0 rows in set. Elapsed: 0.007 sec. 
```

Now you obviously cannot insert anything to this table, because:
```
>>> insert into table2 (EventDate, Id) values (1234567890, 2)

INSERT INTO table2 (EventDate, Id) VALUES

Received exception from server (version 20.9.3):
Code: 6. DB::Exception: Received from localhost:9000. DB::Exception: Cannot parse string 'some_string' as Int32: syntax error at begin of string. Note: there are toInt32OrZero and toInt32OrNull functions, which returns zero/NULL instead of throwing exception.. 

1 rows in set. Elapsed: 0.002 sec. 
```

**How to reproduce**
* Which ClickHouse server version to use: 20.9.3
* Which interface to use, if matters: I used standard CLI

**Expected behavior**
Currently ClickHouse doesn't check types compability while setting a DEFAULT value for a column. Maybe ClickHouse should validate DEFAULT values for type compability?

return constraint_ast->as<ASTConstraintDeclaration &>().name == constraint_name;
                }))
        {
            if (if_not_exists)
                return;
            throw Exception("Cannot add constraint " + constraint_name + ": constraint with this name already exists",
                        ErrorCodes::ILLEGAL_COLUMN);
        }
        auto insert_it = metadata.constraints.constraints.end();
        metadata.constraints.constraints.emplace(insert_it, std::dynamic_pointer_cast<ASTConstraintDeclaration>(constraint_decl));
    }
    else if (type == DROP_CONSTRAINT)
    {
        auto erase_it = std::find_if(
                metadata.constraints.constraints.begin(),
                metadata.constraints.constraints.end(),
                [this](const ASTPtr & constraint_ast)
                {
                    return constraint_ast->as<ASTConstraintDeclaration &>().name == constraint_name;
                });
        if (erase_it == metadata.constraints.constraints.end())
        {
            if (if_exists)
                return;
            throw Exception("Wrong constraint name. Cannot find constraint `" + constraint_name + "` to drop.",
                    ErrorCodes::BAD_ARGUMENTS);
        }
        metadata.constraints.constraints.erase(erase_it);
    }
    else if (type == MODIFY_TTL)