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/setupkey_test.go

@@ -237,6 +237,7 @@ func TestSetupKey_IsValid(t *testing.T) {
 func assertKey(t *testing.T, key *SetupKey, expectedName string, expectedRevoke bool, expectedType string,
 	expectedUsedTimes int, expectedCreatedAt time.Time, expectedExpiresAt time.Time, expectedID string,
 	expectedUpdatedAt time.Time, expectedAutoGroups []string) {
+	t.Helper()
 	if key.Name != expectedName {
 		t.Errorf("expected setup key to have Name %v, got %v", expectedName, key.Name)
 	}