Fix NativeLabelTranslatorStrategy whitespace bug

This bug fixes problem in "_action" column in datagrid table. "_action" was transformed into weird text: " Action" (with space in begining).

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | partialy #640
| License       | MIT