GUI button label is not correctly translated

[halirutan]

If you set a different language than English, the search filter button is not correctly translated. In the image below, it is always "Filter" and "Float" no matter the language settings I have. The tooltips for these buttons are not translated either

The reason for this is that the string values are initialized as static fields in org.jabref.gui.search.SearchDisplayMode when the user language was not loaded. Therefore, they will never be translated.

[lenhard]

Should be fixed by #3327