Various improvements

database/Dockerfile

gms-client/gms-client-lib/pom.xml

...rc/main/java/it/inaf/ia2/gms/client/call/BaseGmsCall.java

gms-ui/src/components/GroupsBreadcrumb.vue

gms-ui/src/components/MembersPanel.vue

gms-ui/src/components/modals/AddGroupModal.vue

...n/java/it/inaf/ia2/gms/controller/HomePageController.java

...main/java/it/inaf/ia2/gms/manager/GroupStatusManager.java

...a/it/inaf/ia2/gms/persistence/InvitedRegistrationDAO.java

...main/java/it/inaf/ia2/gms/persistence/MembershipsDAO.java

...main/java/it/inaf/ia2/gms/persistence/PermissionsDAO.java

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

...inaf/ia2/gms/persistence/NestedGroupsIntegrationTest.java