change structure of identities in api and bindings

bindings/contact.go

bindings/e2e.go

cmd/broadcast.go

cmd/init.go

groupChat/groupStore/store_test.go

groupChat/manager_test.go

storage/user/info.go

xxdk/cmix.go

xxdk/e2e.go

xxdk/identity.go

xxdk/permissioning.go