Support multi users and rbac

[juherr]

Checklist

• I checked other issues already and found no answer
• I checked the documentation and found no answer
• I am running the latest version and the feature i am requesting is not implemented there

Describe the problem you are trying to solve

Currently, only one user is supported with all privileges. It is not a problem for a private instance but becomes dangerous when the instance is shared (especially the delete operations).

Describe the solution you'd like

Replace the mono static user by users stored in database.
It should be possible to enable or disable any crud operation one by one by user or role.

Describe alternative solutions or features you've considered

The user storage could be delegate to a 3rd party backend like okta or any other saas solution.

Additional context

Related to #82

[goekay]

It is not a problem for a private instance but becomes dangerous when the instance is shared (especially the delete operations).

for a proper solution, we should have auditing of modifying operations. that way, an admin can track which user did what. i don't want to open pandora's box and cause more work within current PRs, but something for future.