Add group_vars/all into roles

This is related to NAT-680 'inventory restructure' - some of data is moved from group_vars/routers to group_vars/all. Hence, the need to load group_vars/all folder in almost all roles, except base_config_checks.

requested review from @simone.spinelli

assigned to @Aleksandr.Kurbatov

mentioned in commit d0fa6e83

merged