When creating custom prototypes, one can configure a factory method to convert the attribute's value from/to a string or byte array. It's not possible to use an integer or a float value as an argument/return type, though, even if you set a value type of integer ("i") or float ("f"). Trying to fetch/save an entity containing an attribute using this prototype will throw the following exception:

```
Error encountered converting value of class MyEnum to type specified in attribute 'myEnumAttribute' of entity 'MyEntity'.
Conversion exception is : EOAttribute adaptorValueByConvertingAttributeValue(Object):
Unable to convert value of class java.lang.Integer for attribute 'enumAttribute' in entity 'MyEntity' to adaptor type EOAttribute.AdaptorBytesType.
Check the signature of the conversion method MyEnum.toInteger().
```

This pull request adds the ability to configure a factory method that receives numeric values as an argument and a conversion method that returns numeric values. For instance, it allows the creation of enum prototypes that translate from/to a number in the database.

I'm testing this change using an Oracle database, and everything has been working fine so far. I'll try to test it on other databases as well.

…tabase

Complements the previous commit by converting numeric values from the database to custom types using an attribute's `valueFactoryClass` and `valueFactoryMethod` properties. The parameter type passed to the `valueFactoryMethod` adheres to the `valueType` configured in the EOModel. It must be a reference type (java.lang.Integer, java.lang.Long, etc.), not a primitive type.

The `DateJDBCColumn` class was deprecated in favor of `ERXEnhancedJDBCColumn` to accommodate this change. I'm not sure about the impact of this change on Wonder users, but it doesn't seem too risky. Please, let me know if I'm overlooking something.

This is not the final solution. It would be great to fix it in the `NSSelector` class instead. 🤔