Completed search functionality; fixed paginator issue

gms-ui/.env.development

gms-ui/src/components/GenericSearchResults.vue

gms-ui/src/components/GroupsPanel.vue

gms-ui/src/components/MembersPanel.vue

gms-ui/src/components/Paginator.vue

gms-ui/src/components/PermissionsPanel.vue

gms-ui/src/components/TopMenu.vue

gms-ui/src/store.js

...in/java/it/inaf/ia2/gms/model/response/PaginatedData.java

gms/src/main/java/it/inaf/ia2/gms/service/SearchService.java

...rc/test/java/it/inaf/ia2/gms/model/PaginatedDataTest.java

.../test/java/it/inaf/ia2/gms/service/SearchServiceTest.java