Create new Account types

[Naapperas]

We should have a clear distinction between the various users of NIJobs: Admins, Companies and Users. As such, each one should have a corresponding Account type.

Admins should keep their current functionality.

Company accounts should contain a reference to their respective company but nothing else changes. Later on we could associate multiple accounts to one company. We could also add the ability to merge accounts if something goes wrong.

User accounts should be able to upload information such as their CV, personal information, fields/techs of interests, preferred type of work, profile picture, "preferred locations to work", socials. We should be able to use these preferences when searching, but this should be an "opt-in" feature.

[Naapperas]

This should be partitioned in 3 different PRs.

[Naapperas]

Be careful with GDPR when implementing User accounts