Add user entity access and login time to JSON:API

Problem/Motivation

I want to get access to the access or login time to fetch a custom entity, which I then display to the user as new (since last login or similar).

Steps to reproduce

Just request /jsonapi/user/user/uuid and see that only "created" and "changed" is returned, but not the timestamps of "login" und "access" which are also available in the users_field_data database table (and I guess are updated via some Drupal subsystem hooks/events)

Proposed resolution

just add them to the list of fields returned.

Remaining tasks

Someone has to add them from the core team or tell why these available data is ommitted.

User interface changes

none

API changes

none

Data model changes

none

Release notes snippet