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/idp/auth0_test.go

@@ -65,6 +65,7 @@ func (mc *mockAuth0Credentials) Authenticate() (JWTToken, error) {
 }
 
 func newTestJWT(t *testing.T, expInt int) string {
+	t.Helper()
 	now := time.Now()
 	token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
 		"iat": now.Unix(),