Userinfo fails on inital login

[mhinkie]

Describe the bug
After the first login, io.github.patternatlas.api.rest.controller.UserController#user is called by the UI to get the Username to display on the UI. At this point the user is not created in the patternatlas db since this only happens after some request is sent that causes a privilege/role check for authorization, which does not happen for userinfo.

Expected behavior
Userinfo should call the function responsible for creating/checking initial users in the database (see io.github.patternatlas.api.security.ResourceSecurityExpressionRoot for the associated checks), to ensure the userinfo call does not fail.