MDL-40044 Roles: Added role_capability_updated event and replaced related add_to_log
MDL-40044 Roles: Added role_allow_*_updated events to replace add_to_log on role allow page

Added events:
1. role_allow_assign_updated
2. role_allow_override_updated
3. role_allow_switch_updated
MDL-40044 Roles: Updated role_assigned and role_unassigned event to remove add_to_log