Remove loading from list_component_scope.vue

The following discussion from !154165 (merged) should be addressed:

• @arfedoro started a discussion:

  question (non-blocking) ❓

  Not related to this MR, but I think we can remove loading from list_component_scope.vue

  This component was previously loading policy scope separately, that's why this loader was introduced.

  But now policyScope is a part of graphql and is loaded within policy list and after that isLoadingLinkedSpps can be removed as well.

  What do you think?