Revise the need for a custom user model #365
Description
During the development of v2.0 the project switched from using the default user auth to a custom user model. The main reason was probably related to the handling of password reset, captcha, the idea of requiring an ORCID and other auth things. However, a lot of logic ended up being associated with the user model that should have been linked to the person model. We need an in-depth revision to simplify or remove all this unnecessary code, perhaps even fallback to the default user model.
See #364 for an example.