Extend linter rules (#1300)

- dupword checks for duplicate words in the source code
- durationcheck checks for two durations multiplied together
- forbidigo forbids identifiers
- mirror reports wrong mirror patterns of bytes/strings usage
- misspell finds commonly misspelled English words in comments
- predeclared finds code that shadows one of Go's predeclared identifiers
- thelper detects Go test helpers without t.Helper() call and checks the consistency of test helpers

management/server/event_test.go

@@ -11,6 +11,7 @@ import (
 
 func generateAndStoreEvents(t *testing.T, manager *DefaultAccountManager, typ activity.Activity, initiatorID, targetID,
 	accountID string, count int) {
+	t.Helper()
 	for i := 0; i < count; i++ {
 		_, err := manager.eventStore.Save(&activity.Event{
 			Timestamp:   time.Now().UTC(),