Improve initial 'get started' period for organizers

[Gerviba]

US: As a user I don't want to "go to /c/e endpoints then log out somehow then relog or sg. like that". I want a clear view where I can see my granted roles, refresh my roles and go to the admin page.

AC:

Create a page apiBaseUrl/lemmein:

• Show the current roles associated with the user or a login button if there are none
• Create user by logging in
• Check for permissions to add to the user (run this checks not just the first time a user was logged is)
• Add permissions to the page (with permitAll)
• Use colors similar to the admin and use the tenant accent color

Create a new entity UserGrantEntity:

• Check by email (both providers) or neptun
• Add the option to grant group, role, permission or permissionGroup
• Groups and roles can: DO_NOT_CHANGE, OVERRIDE
• Permissions and permission groups can: DO_NOT_CHANGE, OVERRIDE, GRANT

[linear]

KIR-463 Improve initial 'get started' period for organizers