Fix business logic due to changes in FH documentation

• 6.2.10. Fix updating user in accordance with point 4c (User is allowed to execute request only if roles are changed according to the rules table 'Changing the Roles of a User').
• 6.2.7. Fix getting a list of users according to point 5 (Filter: if (Ro-MU-CA not in User.Roles) then USERS where Participant == User.Participant).
• 6.2.11. Fix updating roles in accordance with point 5 and rules table 'Changing the Roles of a User'.
• 6.2.12. Fix deleting user in accordance with point 5 (Check to ensure the user-to-remove is not the last participant-administrator of the Participant of the user)
• add SD_ADMIN_ROLE (Ro-SD-A) to GET "/participants/{id} in Security config