Fix group chat formatting, comments, and spelling

bindings/group.go

groupChat/groupStore/dhKeyList.go

groupChat/groupStore/group.go

groupChat/groupStore/group_test.go

groupChat/groupStore/store.go

groupChat/groupStore/store_test.go

groupChat/internalFormat.go

groupChat/internalFormat_test.go

groupChat/makeGroup.go

groupChat/makeGroup_test.go

groupChat/manager.go

groupChat/manager_test.go

groupChat/publicFormat_test.go

groupChat/receive.go

groupChat/receiveRequest.go

groupChat/receive_test.go

groupChat/send.go

groupChat/sendRequests_test.go

groupChat/send_test.go

groupChat/utils_test.go