to_timestamp(epoch) not supported yet

**Failed SQL**
```
select updated_at
from orders
where updated_at>to_timestamp(1730562810);
```

**Logical Plan**
```
[cubesql::compile::query_engine] Initial Plan: Projection: #orders.updated_at
Filter: #orders.updated_at > str_to_date(Int64(1730562810))
TableScan: orders projection=None
```

**Version:**
1.1.2

internally to_timestamp calls are converted to str_to_date function which does not take into account of to_timestamp(double)