Add Spring Security expressions

[ikyranas]

Goal

The goal of this task is to achieve multitenancy on the resources using the Spring Security expressions.

Steps

• Bring up the development deployment.
• Use Spring Security annotations for the admin user.
• The admin should be able to search/filter content using the type of the resource, its size and its creator.
• Use Spring Security annotations for the creator role.
• Use Spring Security annotations for the consumer role.

Definition of done

The issue will be considered closed when the requests are authorized properly and the corresponding integration tests are working properly.

[ikyranas]

This is closed by #35 .