Adding Enum Field and to_dict functionality

Hello everyone.
We have found ourselves (Cuenca), using and reusing several functionalities in some of our projects, which are, at the moment, not implemented in this project. For this reason we created a python file where we implement this functionalities, but since we use them in different projects we have been copying and pasting this file.

We would like to add some of this functionalities to this repository for everyone to use, such as an Enum field (present in this repository) and a to_dict functionality inside the BaseDocument class.

In this file you can see how we are currently creating the Enum field, and in this one, you can see how we are implementing it.

Here you can also see how we are using the to_dict functionality. This functionality is self explanatory since it just returns the fields of a model turned into a dictionary to work with. You can see an example on how we are using it, right here, inheriting the BaseModel class we created to add the functionality to all our Models. You can see how we are using this in here.

We would love to have your feedback on this, and also hear your thoughts on this subject, and to know wether it is possible or not to implement this changes. Thanks a lot in advance

Start by reviewing the repository’s BaseDocument API and field implementations, then compare the linked examples in speid/models/helpers.py, speid/models/transaction.py, and speid/models/base.py. Clarify enum and serialization behavior before adding focused tests; done means both APIs have agreed behavior and regression coverage.