Introducing user preferences in ANET

[pacodelcastillolopez]

First implementation of a method to store user preferences in a genery way. By using a preferences table with all possible preferences an ANET user can select and another table that links an specific preference to a value selected by an user.

Initially the preferences table contains preferences related whether or not to receive different flavours of email notifications of type Boolean. Next steps is to define all preferences that must be avialable for users to select and, if needed, extend the GUI to support other components.

Refreres to AB#1216 but it does not close the issue yet, further refinement is required.

User changes

• There is a new menu option (Preferences) that displays all preferences defined in the preferences table. If the user has already selected an specific value for a given preference it is displayed. Otherwise the default value of the preference.

Superuser changes

Admin changes

System admin changes

• application.yml or anet-dictionary.yml needs change
• db needs migration
• documentation has changed
• graphql schema has changed

Checklist

• described the user behavior in PR body
• referenced/updated all related issues
• commits follow a repo#issue: Title title format and these 7 rules
• commits have a clean history, otherwise PR may be squash-merged
• added and/or updated unit tests
• added and/or updated e2e tests
• added and/or updated data migrations
• updated documentation
• resolved all build errors and warnings
• opened debt issues for anything not resolved here