Support enum values by all DBMS

Currently enum values supported by `yiisoft/db-mysql` and `yiisoft/db-pgsql` only.

For other DBMS enum values can be realized using a constraint:

```sql
CHECK (enum_field IN ('value', 'another value', 'something else'))
```

_Updated on 03.10.2023_
Related with yiisoft/db-migration#8