editor field label overrides using alter_semantics hook do only work for English

[otacke]

When using the alter_semantics hook, overriding field labels does only work when the platform is set to English.

cause

When loading the editor, the getLibraryData function https://github.com/h5p/h5p-editor-php-library/blob/050a6845bc61f66aecaf3ed4616ca4596ae17481/h5peditor.class.php#L376-L475 is used to gather information to be passed to the browser, among them

1. the semantics structure https://github.com/h5p/h5p-editor-php-library/blob/050a6845bc61f66aecaf3ed4616ca4596ae17481/h5peditor.class.php#L393 and
2. the translated labels for the platform's default language https://github.com/h5p/h5p-editor-php-library/blob/050a6845bc61f66aecaf3ed4616ca4596ae17481/h5peditor.class.php#L394

If labels are supposed to be overridden using the alter_semantics hook, then $libraryData->semantics already contains the overrides. Both the semantics structure ($libraryData->semantics) and the translated labels ($libraryData->language) will end up in the browser, where in https://github.com/h5p/h5p-editor-php-library/blob/757f7053cd0af26df95b0f12f0141fe98848cea6/scripts/h5peditor.js#L214 the labels of the semantics will be overridden by the translation labels, thus overwriting the changes that were supposed to be set for the labels.