Partial updates using DTOs

Nobody has claimed this yet.

### Feature description

I would like to request a new feature: the ability to pass a DTO to an **update** function in the repository, considering that the DTO has the same properties as the original entity.

To avoid confusion with the actual semantics of the **update** functions, it may be necessary to create a new annotation to instruct Micronaut Data that the argument is a DTO.

Please see the following code for a better example. Suppose that the `@Dto` is the new annotation.

```kotlin
import io.micronaut.data.annotation.Id
import io.micronaut.data.annotation.Dto // New annotation
import io.micronaut.data.jdbc.annotation.JdbcRepository
import io.micronaut.data.model.query.builder.sql.Dialect
import io.micronaut.data.repository.CrudRepository
import io.micronaut.serde.annotation.Serdeable
import jakarta.persistence.Entity
import jakarta.persistence.GeneratedValue
import java.math.BigDecimal

@Entity
@Serdeable
open class Item {

@jakarta.persistence.Id
@GeneratedValue
var id: Long? = null

lateinit var name: String

lateinit var price: BigDecimal
}

@Serdeable
class ItemDTO {
lateinit var name: String
}

@JdbcRepository(dialect = Dialect.POSTGRES)
interface ItemRepository : CrudRepository {

// NEW FEATURE: Update using DTOs.
fun update(@Id id: Long, @Dto item: ItemDTO)

// NEW FEATURE: Update using DTOs.
fun update(@Dto item: ItemDTO)

}
```

I understand that the actual **update** functions allow doing partial updates, but that requires writing a lot of code. Using DTOs is a better way to reuse code, the same object instance of the DTO can be passed from the Controller to the service/repository layers.

Use the ItemRepository example as the entry point, and first read how existing update functions distinguish partial updates from entity updates. Done means the requested DTO-based update forms work without changing the semantics of current update methods, including the variants with and without an id.

Written by the indexing model from the issue text.